Archive of Our Own ^beta

Chapter Text

On the fourth of January, in the year 2004, a boy named Senku is born healthy and strong, if a little on the small side. 

A little under five minutes later, his sister Chisora joins him. Though they don’t know she’s a sister and he’s a brother quite yet. 

“Thousand skies and wise skies,” Ishigami Byakuya’s dearest friend tells him with a smile. “I think they rather compliment each other, don’t they?”

Two years later when an exhausted Byakuya finally dries his eyes and goes to check on his newly adopted children, he sees how they’ve fallen asleep holding hands and thinks, yes, they really do.

Byakuya’s life is full of questions, a constant barrage of small voices that never fails to bring a smile to his face. 

“Why does the sun not run out of light?”

“How do clouds hold rain inside them?”

“Why does ramen take so long to cook?”

Senku and Chisora (now more often called Sora) are always wondering about the world around them, and finding out new things whether from books or from some rather perilous misadventures that leave Byakuya with a few new gray hairs. Whenever one twin gets an idea into their head, the other is instantly on board, no matter how wild or chaotic the results end up being. And sometimes, they seem to come up with the same idea at almost the exact same moment, irrespective of the other—like that one dinner where Sora declared she was a girl and not a boy, and Senku immediately accused her of hijacking his own similar declaration of being a boy and not a girl.  

That’s not to say they’re exactly the same, however. When they get upset, Senku’s far more likely to simply shut down for a while and not say a word, while Sora makes her displeasure known with great enthusiasm. When they get in trouble, Sora sweetly sings her obviously false apologies while Senku wears his sinister grin like a badge of pride. 

They bicker too, just like any other pair of siblings would, over petty little things like who gets to play on the PS4 first or who gets to choose what movie they watch on a Friday night. And their fashion sense is definitely different—Senku tends to dress like a little professor, complete with bow tie and pocket protector, while Sora ties her hair into two low ponytails and prefers clothes that resemble what Byakuya thinks people in the 1960s wore, if sized down considerably. 

But when it comes to science, they’re completely in sync. “We’re going to the moon,” Senku declares to their shocked elementary school class, “and I’m gonna build the rocket that will take us there!”

“We’re going to the moon,” Sora echoes with a challenging edge to her voice as their teacher smiles placatingly, “and once we do I’m gonna find out if aliens are really out there!”

A shared dream, a shared promise. The entire Ishigami family, it seems, yearns to explore the stars, enthralled by the vast beauty of the eternal sky above. Senku is enchanted by the complex dance of engineering and physics that gives humanity the power to explore beyond their own planet. Sora however is taken in by the secrets lying in the rocks and soil of a land far beyond the horizon. 

This ends up being reflected in their studies as well—while they’re both certainly absorbing knowledge of all sorts far beyond that of their peers, Senku’s inquiries take him into engineering and physics, while Sora’s direct her more towards chemistry and biology. Neither twin considers their favored disciplines to be separate, however.

“This way, we’ll learn twice as much in the same amount of time, and then the work will be far more efficient,” Sora says matter-of-factly as Senku nods. 

“And we can teach stuff to each other way better than people who don’t know us.”

Byakuya smiles. “You’ll always have each other’s back then? I’m glad!”

“Well duh,” Senku snorts as Sora rolls her eyes. 

“We came into this world as a pair,” she says, “and so it’s only logical that we’d work together for our goals.” 

Byakuya chuckles. “Of course.”

Though the way they process emotions is a little different, Senku and Sora are both loath to be completely honest with how they’re feeling, especially when to them, there are other things to worry about. 

Besides, there’s no way they’re lonely. Their classmates in elementary school simply can’t keep up with them, and that’s fine. They’ve got each other, after all. The trust the twins have in each other flows as easily as electricity through gold wire, and they can spend entire days just chattering away about various experiments and hypotheses they want to test out. 

There’s no way they could be lonely, even though no one else seems to care about the things they do, even when older kids mock them for their enthusiasm, even when they see groups of their peers gathering together and having fun playing sports and talking about movies and toys and gossip that they don’t understand.

It’s not lonely. 

Some of the other boys whisper about Senku’s fragility, how he’s too weak to even throw a baseball, how uncool it is for him to spend so much time with a girl even if said girl is his own sister. 

Some of the other girls murmur about how standoffish and mean Sora looks, how indelicate and unrefined her mannerisms are, how embarrassing it is that she doesn’t even bother with looking pretty.

It shouldn’t matter. Who needs jerks like them hanging around and criticizing everything they do? Senku never tells Sora she’s not delicate enough to be a real girl, and Sora never tells Senku he’s too weak to be a real boy. 

It’s not lonely. It’s not.

Except sometimes they do wonder what it would be like to have friends other than their twin. Would it be worth it? Would it be fun?

The answers to their unspoken questions come unexpectedly one day, when they’re running an experiment in the local park. A broken part sends Sora to the hardware store while Senku attempts to reconstruct the busted piece, and two things happen simultaneously.

The first is that a group of high schoolers start kicking the device, and Senku is powerless to stop them, especially when they start whaling on him instead. It’s nothing new, but Senku tries his best to protect the device, especially because of the weeks of effort that went into it. But then suddenly there’s another boy, standing between him and his assailants, taking all the hits without even flinching.  

The second is that when Sora leaves the hardware store, a separate group of bullies confronts her, knocking her bag full of tiny screws to the ground and pulling painfully on her hair before running away laughing when one of her hair ties snaps. As Sora blinks back angry tears and starts picking up the screws, a girl kneels in front of her and starts picking them up too. 

“Sorry I couldn’t stop them from breaking it,” the boy says to Senku. “Are you okay though?”

Senku nods numbly. “Um, yeah. Thanks.”

“I can’t believe those jerks had the nerve to mess up your hair too,” the girl says to Sora, pulling a ribbon out of her bag. “Here, you can use this.”   

“Oh.” Sora blinks. “Okay.”

The boy holds out his hand to Senku and pulls him to his feet, brushing dirt and grass off his coat, and despite the close proximity Senku isn’t bothered. “I’m Taiju, by the way.”

The girl smiles as she ties a neat little bow, restoring Sora’s ponytails. The look is uneven now with one bow and one regular hair tie. Sora finds she doesn’t mind. “My name’s Yuzuriha.”

Each Ishigami stares at their stranger with big eyes.

“Senku.”

“Sora.”

The twins don’t believe in the concept of soulmates. But if pressed, they might admit that those moments felt like they were always meant to happen. 

Sora and Senku are eight years old, and their little group has grown from two to four. It’s a neat mathematical equation, and when the twins notice how their new companions blush around each other they’re quick to slide into the roles of teasing best friend. Being around Taiju and Yuzuriha feels as natural as breathing air, and yet distinctly different from being around each other.

Their teachers are initially cheered by the fact that the rowdy Ishigami twins appear to be forming nice, normal relationships for once in their lives…until they realize that the addition of Taiju and Yuzuriha isn’t the kind of neat chemical reaction that results in an inert compound. Instead, they spark and burn brighter and louder than ever, an explosion of creativity and chaos.

Middle school is chaotic enough with Senku and Taiju sharing a class and Sora and Yuzuriha sharing another, but in their second year they’re all together, and no one, no one will be able to forget The Paintball Incident of 2017.

When they graduate, everyone breathes a sigh of relief as the group that’s become known as the Terror Team suddenly becomes Hirosue High School’s problem, leaving behind three years of legendary stories in their wake.

They’re not in high school for very long before another story begins. 

One sunny afternoon in early June, Oki Taiju barges into his school’s chemistry lab and loudly declares to his best friend of seven plus years that he’s about to confess his feelings for a mutual friend of theirs.

“I can’t believe you haven’t said anything in all these years,” Senku says as their classmates stare with wide eyes. “How illogical can you get?” He holds up a beaker of yellowish fluid and grins. “I’ve got something real logical for you right here.”

Taiju, predictably, rejects the offered love potion. “Thanks Senku, but I can’t rely on cheap tricks!” He goes to leave, then stops at the door just before bumping into a girl with the same crimson eyes and green hair as Senku, except she wears it in a single bushy ponytail. “Oh, hey Sora! Almost didn’t see you there!”

“Careful, you big oaf!” Ishigami Chisora scowls and maneuvers around Taiju with a canvas bag in her arms. “You nearly made me drop the specimens!”

“Oh, fantastic, I was about to bug you about being late,” Senku says as his twin sister carefully sets the bag down on their table with a sound like a bunch of clattering rocks. “Something interesting is happening today, you know. Taiju here’s about to confess to Yuzuriha.”

Sora raises an eyebrow. “Are you now?” she says to Taiju. He nods. 

“I know she might not return my feelings,” he said, “but I just want her to know!”

Sora narrows her eyes. “Well then what are you waiting for, idiot! Get going!”

“Ah, right!” Taiju takes off down the hall, and Sora clicks her tongue. 

“Guess I owe you three thousand yen,” she says grumpily to Senku as he pulls a stone sparrow from her bag. He smirks. 

“Well you could have tried to discourage him from confessing, if you really wanted Yuzuriha to do it first.”

“Are you fucking kidding me?” Sora practically yells. “I’m just glad it’ll be over soon! Do you KNOW how many sad Yuzuriha faces I’ve had to look at because she somehow doesn’t see that Taiju would hang the moon and stars for her? Too many!”

“Wait, you guys were betting on who was going to confess first?” Hisashi asks. 

“If we had to spend the rest of our days around those pining idiots, we thought we might as well try to have fun with it,” Senku shrugs. 

“It’s really such a shame,” Sora says, readjusting her ponytail—she’d switched from twin tails to a single one when high school started. “I was planning on preordering Persona 5: Royal with my winnings.”

“You guys live in the same house though,” Noboru says. “Don’t you just share video games?”

Senku raises an eyebrow and Teruko lets out a snort of laughter, pointing at Noboru. “Only child alert!”

“Ha! Clearly.” Sora says. She blinks, then sniffs the sink nearby. “Okay, who’s the idiot that poured gasoline down the drain?”

It was supposed to be a good day.

Taiju was going to confess to Yuzuriha, they’d both probably cry with happiness about it, and then Senku and Sora would make fun of them for taking so long and tell them all about their experiments with the stone sparrows.

Instead, a green light appears on the horizon, and as he and Sora stand by the window staring, they exchange a glance.

Possible danger too fast no time to hide gotta stay close can’t be separated don’t get separated—

They quickly stand back to back, arms interlocked, and brace for impact. 

If we die, we go out the same way we came in.

Together.

Three thousand, seven hundred, and nineteen years after a mysterious green light washes over the earth, Ishigami Senku blinks up at the sky through the cracks in his stone shell and takes a deep, shuddering breath.

The first thing he says is “Damn.”

The first thing he hears is “Get the hell off of me!”

Ah. Right, because they made sure to avoid being separated, Sora is lying face down in the dirt under his back. 

“Oh, can’t handle a little weight?” Senku can’t help but snort at her. “Not even to preserve the site’s scientific integrity?”

“It isn’t a little weight if you’re pressing down on my damn spine,” Sora grumbles, though she hasn’t moved much. Senku laughs, and it’s slightly strained.

He hadn’t realized how much he missed her voice. 

Eventually they manage to free themselves completely from the dirt and moss and stone covering their bodies, replaced with some vines for modesty.

“Not that I care about seeing your ugly ass,” Senku cackles as Sora rolls her eyes at him.

“You’ve got an identical ass, idiot,” she says, flicking his forehead. “Though not the same brains, evidently.”

Senku swats her hand away and sticks his tongue out at her. “We’re fraternal twins, not identical, moron. It only makes sense that I’d win out on that lottery.”

Sora snorts. “You fucking wish, asshole!”

 They quickly run the calculations and figure out that it’s now April first of the year 5738, which Senku carves somewhat ceremoniously into a nearby tree. 

“How long do you suppose it’ll take to bring it all back?” Sora says as they survey their surroundings from a hilltop.

Senku shrugs. “Dunno. Could take the entire rest of our lives.”

Sora hums, the wilderness around them feeling like an ocean of green, and the two of them tiny specks in its vastness. “Well we’re not dying before we recreate Minecraft.”

“Obviously.”

Survival in this new world is much, much harder than Minecraft though, and decidedly less fun, though the Ishigami twins are no strangers to grueling hard work.

“Imagine punching a tree for wooden tools first,” Senku snorts as they experiment with different ways of breaking off flakes of chert from larger stones. 

“You’re more than welcome to try,” Sora cackles. “I’m not gonna kiss your boo boos better like Dad does though.”

The two of them freeze. 

Senku’s fingers hover over the rock he’s reached for.

Sora’s tighten on the piece of chert she’s holding. 

“…As if I’d want your gross lips anywhere near my hands,” Senku says, picking up the rock.

Sora’s fingers relax only slightly. “Ha. Yeah.”

There’s no time for that right now. They’ve got to focus on not dying, after all. And so they continue, acquiring stone tools and food and clothing and shelter. It’s not easy, not by a long shot, but it would be a lot harder if it was just one of them. Not that Senku can even picture the thought of it, though. The Ishigami twins have always been a unit, working in tandem towards the next crazy goal. 

Like a binary star, Dad used to say. If you’re standing far away, they almost look like one brilliant point of light, but they’re still two individual ones, both equally beautiful in their own right.

Don’t think about it. Don’t.

“Hey, you’ve still got some stone on the back of your neck,” Sora says, prodding Senku’s head a little more sharply than is necessary. 

Senku reaches back and feels the little patch of stone. “Hmm. It doesn’t seem to be causing me any problems. How’s it look?”

Sora pokes at it. “It’s kind of fused to your skin,” she reports. “I can see some baby hairs that are still completely stone, too. Though there doesn’t seem to be any residual damage like the cracks in our faces.”

Senku’s got one crack on the left side of his face, going down his forehead with a little spike in the middle. Interestingly, Sora has the exact same mark only mirrored on the right side of her face. Kind of a funny coincidence, if it is one.

“Kukuku, this is actually rather convenient,” Senku remarks. “Now we’ll have more opportunities to study the stone on flesh, as long as we preserve this little patch.”

“Hell, we gotta take what we can get out here,” Sora says. “Especially since we don’t have many other leads on what happened.”

Once they have their little treehouse all put together, the two of them stand proudly under it, before high fiving with a triumphant cackle.

“Man, you remember how we always wanted one of these?” Sora says. Senku nods. The twins had dreamed of building their own observatory once upon a time, but there was no way they could have had a treehouse in the bustling metropolis of 21st-century Tokyo. 

“I have to say,” he says, “this would probably be a lot harder if we weren’t two people.”

“Well then,” Sora smirks, “it’s a good thing we came as a package deal.” 

Senku chuckles. “Sure is. Look out humanity, the Ishigami twins are gonna save your asses!”

Chapter Text

They find Yuzuriha and Taiju pretty quickly, all things considered. And while ideally they’d have the entire team back together in a few days, it ends up not being so simple. It’s easy enough to conclude that the nitric acid dripping from the bat cave near to where the twins woke up had something to do with their revival, but figuring out where to go from there is…tricky.

“Okay, so that was what, maybe 250 milliliters?” Sora says after Senku’s dumped a whole cup full of the yellowish fluid over Taiju’s statue to no effect. “We were likely getting steady exposure over a long period of time, since we were buried in the dirt and all.”

“So maybe slow exposure is better,” Senku frowns. “But then how long? And would we have to immerse the entire body in acid, or are there key points to target that would be more effective?”

Sora crosses her arms and furrows her brow, and Senku can tell what she’s thinking. If this kind of thing requires sustained exposure for years at a time, what would that mean for Yuzuriha?

“Well,” she scoffs. “We better start experimenting then.”

There’s no use in dwelling on hopeless theoreticals. Only experimentation and results will give them real answers. Or at least enough answers to move onto new questions. 

They drag Taiju to the cave and set him up under the dripping acid and check on him periodically. Sora wants to bring Yuzuriha to the cave too, but Senku reasons that the camphor copse is much too far away for them to bother wasting the energy transporting a heavy statue over the uneven terrain. Besides, if Taiju wakes up and runs off he’ll ten billion percent head for the old schoolyard, so it’ll be better to leave a message with Yuzuriha.

“Then why not just put up a fence around the cave with a big sign saying HEY DUMBASS JUST WAIT A SECOND?” Sora grumbles. 

“Animals could knock it down,” Senku points out. “Besides, Yuzuriha could be damaged if we try transporting her that far.”

“Ah.” Sora looks away. “Right.”

The pinch around her eyes is familiar, but not any less sobering to Senku. Because it’s not about getting grounded or Senku stealing the last cookie this time. It’s about her best friend. And Senku may not be nearly as close with Yuzuriha as his sister is, but he gets it.

“She’ll be safe with the tree,” he says. “She lasted this long, right?” 

“…Yeah,” Sora nods, suddenly looking a lot more confident. “She’ll be fine.”

That doesn’t stop Sora from going out to the camphor copse almost every other day to check, but Senku can hardly blame her. He’s constantly checking on Taiju too, after all.

It’s Sora who ends up seeing him revived first, actually. While trekking out to see Yuzuriha one day, she stumbles upon a very obvious trail of trampled grass and foliage as she gets closer, then suddenly hears Taiju’s booming voice loudly declaring his everlasting love for Yuzuriha as he cries.

She gives him approximately five seconds of melodramatic pause before she steps into view. “Geez, you should save all that for when she can actually hear you, idiot!”

“WAUGH!” Taiju falls over himself in astonishment. “SORA?!”

“In the flesh,” Sora huffs. “Just like you now, unfortunately for my poor eyes.”

“You—Hey! I’m covered up!” Taiju shakes his head. “Wait, so if you woke up, does that mean—“

Sora grins. “Sen’s awake too, yeah. We are a set, after all.”

She has Taiju carry Yuzuriha back to camp, after wrapping her friend in leaves of course. This is also a good idea because it forces Taiju to carefully set Yuzuriha down on the ground before he tries to bowl over Senku in happiness, allowing Sora’s brother a good half-second start to screech and run in the opposite direction while Sora goes to get some extra clothes. 

“Hey, I just realized,” Taiju says as he ties a rope around his new leather skirt. “What’re the letters you’re wearing?”

Senku and Sora glance at each other. Senku’s outfit has a large capital letter E and the = symbol on his left shoulder. Sora’s however has mc2 on her right. 

“It’s the energy-mass equivalence formula,” Senku explains. We thought of it when trying to figure out how we were able to wake up.”

“We concluded the mass of the stone was turned into the energy of our thoughts, weakening it enough to be broken by the acid,” Sora says, tapping her head. “Energy and matter, two sides of the same coin. We figured that’s something worth remembering.”

“Ohh!” Taiju nods. “Cool!”

“And since I’m the older twin, I got the E, which comes first,” Senku says, grinning. Sora shoves his shoulder and he squawks.

“It was a rock paper scissors match,” she scoffs. “Totally arbitrary. But it doesn’t matter anyway, because it’s not like one is better than the other. They’re just the same thing but in different forms.”

“Just what someone would say after they lost a rock paper scissors match,” Senku says. He ducks behind Taiju with a yelp when Sora swings at him again.

Taiju gets an idea to make alcohol for nital using grapes he found while foraging, and all three throw themselves into the work with enthusiasm. To ensure Yuzuriha is safe from the elements, they decide to keep her inside the treehouse, albeit behind a curtain since it gets a little unsettling seeing the seemingly dead stone stare of your friend looking at you when you sleep. 

Months pass. Experiment after experiment after experiment, bird after bird after bird. Taiju does all the heavy lifting, carting around the brandy basins and chopping wood for the fire under the distiller. The twins are doing the science, splitting the trials between them just like they’ve done in all their past projects. A well oiled machine, each picking up the others’ slack when they slow down. 

Spring rolls around, and they finally have it. The perfect formula. Taiju whoops and cheers at the sight of the healthy little sparrow taking flight, and Sora and Senku cackle in delight as they share a high five.

They have to wait a few days before they can collect enough nitric acid from the cave to revive Yuzuriha, but those days are abuzz with excitement as they chatter amongst themselves about future plans.

The sun finally rises on the dawn of Yuzuriha’s revival, and Senku and Taiju decide to go retrieve the nitric acid while Sora starts breakfast for the four of them. 

And then disaster strikes. Because Senku’s luck is apparently cosmically bad, and lions seem to have an uncanny sense for sudden dramatic entrances.

And now there’s a famous wrestler looking down at him and Taiju with a calm, unreadable expression, and alarm bells are screaming in Senku’s mind. 

Taiju seems to think that Shishio Tsukasa’s pragmatism involving the lion meat is evidence enough for his good character. But all Senku can think about is that there’s no way Taiju is strong enough to defend against this guy, and when it comes down to it, the person most likely to be vulnerable to the newcomer is Sora.

 So when Tsukasa asks if they’re the only ones awake as they walk towards camp, he momentarily freezes, suddenly unsure of what to say. He can’t hide Sora’s existence, and there’s no way to break away to warn her about the potential danger. Of course, all deliberation goes out the door when Taiju decides to take matters into his own mouth.

“Just us and Sora!” He says, grinning. Senku fights the urge to punch him in the side.

“Sora?” Tsukasa asks. Senku hates the sound of her name on the man’s tongue. 

“…My little sister,” he says. Tsukasa blinks, then suddenly smiles enigmatically.

“You have a little sister? How old is she?”

Senku does not like this conversation. “We’re twins, though the way she sees it, I’ve put her through enough bullshit to age her way past the five minute gap.”

Tsukasa chuckles. “Mmm. I’ve definitely met several older brothers who say similar things,” he says. “Little sisters can be quite the handful no matter how big the age gap, it seems.”

Senku doesn’t know what to make of that.

They get to camp, where Sora is minding a pot of stew over the fire. Her eyes widen when she spots Tsukasa, sending a piercing look towards Senku that clearly says WHO THE HELL IS THAT?!

What comes out of her mouth however is a much more measured, “Uhhhh…whatcha got there?”

Senku sends a look back that attempts to convey THIS WASN’T PART OF THE PLAN OKAY GIVE ME A BREAK and then says “Some more help.”

After some rather uncomfortable introductions, Senku suggests that Taiju and Sora go to the beach to collect more salt to preserve the lion meat they’ve brought back, which they do so gladly. In the meantime, Senku sets about sewing Tsukasa some proper clothes.

“Your sister,” Tsukasa says. Senku doesn’t flinch, instead continuing to sew.

“Mm? What about her?”

“She seems…afraid of me.”

Senku scoffs. “Well you’re a stranger, I think she’s warranted a little caution.” He keeps sewing.

Eventually, Tsukasa speaks again. “You do know that I would not hurt her, right?”

Senku looks up at him. Tsukasa is staring at him with a strangely earnest expression, his cool gaze replaced with wide eyed pleading. “I am aware that I am…intimidating, especially to young women. But she has nothing to fear from me. I promise, I will protect her from all harm.”

Senku blinks. Then, he frowns. “Weird thing to say about my sister, a girl you just met,” he says. 

Tsukasa’s eyes widen. “Wait, I didn’t—I don’t mean to suggest any impure intentions!” He says. “I only wish her fears to be assuaged, really. I mean I’d protect all of you from the predators, not just her.” 

“Hrm.” Senku turns back to his sewing. “I’ll talk to her about it. It’s true it wouldn’t be good for team cohesion if you two couldn’t get along.”

Tsukasa exhales. “Thank you.”

“But you’re also gonna have to earn her trust naturally. Sora’s like a cat, you can’t force her to come to you or you’ll get scratched. Badly.”

Tsukasa nods. “I completely understand. I shall prove myself through dedication and honest work.”

Hmm. Either he’s a master manipulator, or he’s genuinely one of those weirdly chivalrous types. Maybe they can work with this. Maybe. It’s still too early to tell. 

When Sora and Taiju make it back, Senku can tell there’s been a conversation. Taiju is walking closer to her, and no matter where they go he’s always between her and Tsukasa. And when they prepare for bed and Tsukasa volunteers to sleep on the ground, Senku takes note of how Sora readjusts the curtain covering the corner of the treehouse where Yuzuriha’s statue is, obscuring it completely and adding a sign that says “SORA’S STUFF—GIRLS ONLY.” 

There are enough risks to letting him walk around without putting Yuzuriha in harm's way. Until they can get a better sense of Tsukasa and his intentions, not a word will be breathed about the revival fluid.

A few days pass. Tsukasa is a hard worker, polite, affable, and nothing but a gentleman to Sora, even offering to help her with her own tasks when the others are also around but busy. If Sora were the type of girl to be charmed by a handsome and muscular young man, she’d probably really enjoy this. 

But she’s not, and instead Tsukasa’s offers become clear annoyances. Senku’s not sure that Tsukasa is aware just how pissed Sora is whenever he implies she needs help. To him, she probably just seems nervous and shy, always giving excuses or saying Tsukasa can help out in other ways. At least an angry Sora is better than a straight up terrified Sora. Senku’s used to Angry Sora. He’s not used to Scared Sora. 

He doesn’t want to be used to Scared Sora. 

Things seem to be going alright though, until one day when he and Tsukasa are collecting shells for lime while Sora and Taiju are building a new kiln. 

“Senku,” Tsukasa says. “You’re protective of your sister, are you not?”

Well that doesn’t sound ominous at all. “I mean, sure? She might be a pain in the ass, but I wouldn’t want to see her get hurt. She can take care of herself most of the time though.”

“You would want her to live in a world where she can be safe and thrive, right?” Tsukasa continues. “A world in which she does not have to live in fear of those who would take advantage of her.”

“…I’d think everyone would want to live in a world like that,” Senku says. Tsukasa nods.

“Quite true. But it is our duty now to build that world with our own two hands, as those who have the strength and intelligence to do so.”

His face grows dark. “There are many who would stand in our way.”

He tells Senku a story, about a boy and his sister and seashells and a cruel man. 

And then he kills someone right in front of him.

“Let’s build a better world, Senku,” he says as Senku stares at the chunks of stone scattered across the sand. “A world where the young and innocent are free from all the sins of modern society. A world where little girls can be mermaid princesses, a world where young women need not fear the intentions of men. We shall take on this responsibility, as the strong older brothers of the new generation of humanity itself.”

Senku is quiet for perhaps a little too long, but he finally finds his voice. “Well. That’s certainly a compelling argument. But you do have to realize that Sora and Taiju are going to find the whole smashing thing a bit frightening.”

“That is true, but they will come to understand the importance of cleansing the earth of such evils,” Tsukasa says.

Senku puts up his hands. “I just need some time. If we push this too hard, Sora’s just going to be even more scared of you, and she’ll feel like I betrayed her by siding with you first. Let me talk to her about it and bring her around, okay? She’ll get it if it’s coming from me.”

“Mmm. Alright. I do want her to trust me,” Tsukasa nods. “I shall follow your lead then.”

“Cool, cool.”

Late at night, after checking that Tsukasa is well and completely asleep, Senku shakes Sora and Taiju awake with wide eyes and an expression that screams WE GOTTA GO.

They steal away into the night, making it to the nitric acid cave and reviving Yuzuriha as quietly as they can. It’s not the happy reunion they wished for, but it’s what they’ve got, and despite the tension in their shoulders Sora knows they’re all relieved that at least they’ll be facing the coming storm together. 

“Hakone, then,” Sora says. She and Senku had talked about it before, in hushed late night conversations mostly through sign language and interpreting familiar expressions in a way only they could. Gunpowder was always their backup plan, if Tsukasa turned out to be untrustworthy. There are very few things they have available to them that would be half as effective. 

They set out, trekking over hills and rivers and large patches of brush, all the while catching up Yuzuriha on what they’ve been doing. 

“You’re a bit clingier than usual,” Yuzuriha says when the boys have gone off to collect firewood. Sora pauses in brushing her friend’s hair and looks to the side with a faint pink dusting her cheeks.

“…Sen got to spend six whole months with his best friend,” she mutters. “I can be a little selfish, can’t I?”

Yuzuriha blinks, then smiles warmly and laces her fingers into Sora’s. “I missed you too, Sora-chan.”

“You weren’t even conscious,” Sora says, rolling her eyes. Yuzuriha laughs.

“Maybe not the whole time, but early on I was definitely thinking about all of you, whether everything would be okay. And even if things are…complicated now, this time I know for sure it’ll be okay, because we’re all together now.”

They hear the boys arguing over something silly as they approach, and Sora smirks.

“At the very least, it won’t be boring.”

Sora should really know not to tempt fate by now huh. A thick plume of dark smoke snakes into the air from the fire Taiju’s just created from their first batch of gunpowder, and she frantically scrambles for something to carry water in.

“Quick, put it out! Ugh, maybe we can fan away some of the smoke? But then—” 

“Look over there!” Everyone follows Yuzuriha’s finger to a second plume of smoke rising in the distance. Their jaws drop.”

“A forest fire?!” Taiju asks. “Or maybe—?”

“Another survivor,” Senku breathes. “They might assume our fire is just the volcano though—should we burn it higher?”

“Wh—NO WAY!” Sora exclaims. “We are NOT risking discovery NOW of all times!”

“But there could be another nitric acid cave!” Senku protests. “Or a whole settlement with even better resources!”

“Or Tsukasa could catch up and KILL US ALL!” Sora screams.

“WAIT!” Yuzuriha gets between them, arms wide. “Put out the fire! I’ll go check on the other one!”

Senku and Sora stare at her. Taiju looks like he’s going to cry. 

“This Tsukasa sounds dangerous, but Senku-kun’s right, we don’t want to lose this opportunity. So I’ll go check, see if there are any people out there. Okay?”

Senku and Sora look at each other, and then Senku picks up the water skin and dumps it over the fire as Sora exhales in relief.

 “I’ll be right back then,” Yuzuriha says.

“Maybe I should go with you,” Taiju says. Yuzuriha shakes her head.

“The twins will need your help to compress the gunpowder,” she says. “Besides, I know how to hide, and I’m much less easy to spot in the forest than you three.”

She heads off, and Senku rubs the back of his neck awkwardly as he glances at Sora. 

“Hey. You know I don’t—“

“I know,” Sora huffs, crossing her arms and going back to the sulfur they’ve collected. “Come on, gunpowder won’t make itself.”

Yuzuriha makes her way down the mountain and towards where they spotted the smoke. There is a chance that it’s just a small forest fire, but again, it doesn’t hurt to check. 

Suddenly, there’s a rustling sound and she freezes. “Hello? Is anyone out there?”

And then, amazingly, someone answers. “Hello?”

Yuzuriha gasps. “Yes, over here!”

A blonde girl dressed in blue emerges from the trees, and even in her shock Yuzuriha can’t help but notice that her clothes are clearly indigo-dyed deerskin, with obviously handcrafted stone shoes. She’s staring at Yuzuriha with wide eyes. 

“Well,” Yuzuriha says. “This is interesting.”

Her name is Kohaku, and she doesn’t know anything about nitric acid or reviving people from stone, but she does live nearby, along with her family and apparently about forty other people in her village. When Yuzuriha explains what she and her friends are doing, Kohaku is remarkably generous in offering help.

“This Tsukasa man sounds like he’d become a problem for my own people if not dealt with as soon as possible,” she says. “Of course I’ll help!”

Yuzuriha is quite excited to introduce Kohaku to her friends, but as they get closer Kohaku squints at the mountaintop with a furrowed brow.

“You said you were traveling with three people, right?” she says hesitantly. 

Yuzuriha’s blood runs cold. 

Taiju is crying, Senku is staring at her with the most terrified expression she’s ever seen in her life, and oh yeah, Tsukasa has his hands wrapped around her throat so tight she can’t even speak. 

Un-fucking believable.

“I could kill her right now,” Tsukasa says in that low rumble of his. “It’d be as easy as breaking a twig.”

“You said you wouldn’t hurt her,” Senku says quietly. Sora blinks. He did? Since when? 

Tsukasa hums. “And I will keep that promise. Provided you tell me the revival formula, Senku.”

Sora glares at Senku with as much fury as she can muster. DON’T YOU DARE!!

Senku closes his eyes. 

“Half a kilometer east of the camp, there’s a cave where nitric acid drips constantly from the ceiling.”

Sora’s stomach plummets. 

“Mix three parts nitric acid to seven parts brandy that’s at least 96% pure alcohol. Even the slightest variation and it won’t work, so you can test it on the swallows.”

“Thank you, Senku.” Tsukasa drops Sora, and she falls to the ground in a heap, weak from struggling against him. He steps over her towards Senku. 

“SENKU! NO!!” Taiju rushes at Tsukasa, and is thrown to the side for his troubles, landing with a sickening crunch and rolling over to blink dazedly up at the sky.

Sora struggles in futility to raise herself to her knees. Her brother, her stupid, idiotic, brainless moron of a twin, is looking up at Tsukasa, ignoring her. 

He cracks his neck with a sigh. “Make it quick, will you?”

“Of course. I would not want Sora to see you suffer.”

“Sen,” Sora coughs. Senku’s eyes meet hers in a fraction of a second.

“It’ll be fine, Chi.”

Snap.

Sora can’t describe what’s happening to her. Nothing in her mind can possibly express the feeling surging through every limb, every blood vessel, every cell, every molecule in her body.

It’s not pain. It’s something else, something that goes deeper than the matter making up her physical form. It’s as though the very forces holding her atoms together are screaming in an agony only known by supernovas, spewing the innards of stars like blood pouring out of a wound.

Senku is lying on the ground in front of her, glassy eyes staring up at the sky.

Sky. They both have sky as the latter part of their names. A matching set.

They’re a set. You can’t have one without the other. They’re a set. 

They came in as a set.

They’re supposed to be a set. 

They are a set.

They were—

THEY ARE A SET THEY ARE A SET YOU CAN’T BE A SET WITH ONLY ONE HE’S NOT GONE THIS IS NOT HAPPENING THEY’RE A SET THEY HAVE TO BE A SET HOW DARE YOU FUCK YOU FUCK YOU NO NO NO NO NO NO NO NO NO NO NO NO—

A shadow falls over Senku’s face, blocking out the sky. Sora looks up at Tsukasa. For a moment, she’s happy. He’ll kill her too, and the set will be complete again. Never one without the other—they came in together, they’ll go out together. 

But then he crouches down. And holds his hand out to her.

“I did promise him,” he says seriously, “that I would never hurt you.”

Sora looks down at the hand. She looks at Senku. 

“What?” She croaks.

“I’m not going to hurt you,” Tsukasa says. “It would be dishonoring the wishes of the dead, and besides that, your knowledge of plants and construction will be very important for the pure society I wish to build.”

Sora blinks. 

Then, she spits at him. 

“Fuck. Off.”

Tsukasa stands up. “I understand. It is a cruel thing I have done. But it was necessary. I will leave you be, but know this—my empire will always be open to you and Taiju.”

He walks off, and Sora is left staring after him in disbelief. 

She doesn’t know how long she just sits there, looking at the spot where Tsukasa disappeared. Then her attention is suddenly pulled back to the present by the sound of anguished screaming. 

“SENKU!!! NO!!!!”

“SENKU-KUN!!!”

Taiju is cradling Senku’s limp form to his chest and wailing, Yuzuriha in tears on his other side. Sora crawls over to them and stares at the blank, dead gaze in her brother’s eyes.

“Sora-chan!” Yuzuriha cries, throwing her arms around her. “Oh Sora-chan, I’m, I—“

Sora raises her hand and slaps Senku right in the face.

Yuzuriha and Taiju freeze, staring at her. 

“You BASTARD!!” Sora screams at Senku. “WHAT exactly are you expecting me to do in this situation, huh?! What fucking scheme did you have so far up your damn ass that was so good you couldn’t even tell your own lab partner? WHAT WAS THE PLAN, NUMBSKULL?!”

“Sora-chan?” Yuzuriha squeaks.

“There’s always a plan, a stupid plan this time but there had to be a plan!” She slaps Senku’s face again. “SO WHAT IS IT, GENIUS? HOW ARE YOU GONNA COME BACK FROM BREAKING YOUR GODDAMN NECK?!” 

Taiju blinks. “His neck.” Sora snaps up to look at him. “Whenever he cracked it, it was way louder than it should have been! Why?”

Sora’s eyes widen. “Flip him over!” Taiju does so, revealing the patch of stone at the back of Senku’s neck.

Yuzuriha gasps. “The revival fluid!” Sora scrambles to pull some from her pockets, spilling it over both Senku and herself.

The patch crumbles off.

Nothing.

Happens.

Sora’s shoulders quiver.

“No,” she says, voice small and shaky. “Don’t do this to me.”

She takes a shuddering breath, forehead pressed to her knuckles. “We promised we’d go to the moon together. Remember?”

She raises her head and places a hand over Senku’s. “Come back.”

And Senku blinks.

Chapter Text

“Nice job guys,” Senku says. “You figured it out!”

Taiju, of course, yells. “WHOAAA!! SENKU!!!” He quickly envelops Senku in a crushing embrace, much to Senku’s groaning discomfort.  

“Careful!” Yuzuriha laughs, joyful tears streaming down her face. “You’re going to hurt him if you hug him too tight, Taiju-kun!”

“Oh, right, sorry!” Taiju releases Senku, who looks Sora in the eyes and offers her a smile.

“Can’t get rid of me that easily, right?”

Sora blinks, then rolls her eyes. “As if your sorry ass could go anywhere without me,” she scoffs.

Yuzuriha frowns. “Sora-chan—“

“Excuse me,” a fifth voice says, and everyone turns around. A blonde girl is waving at them hesitantly. “But, ah…is anyone going to explain what just happened?”

“Oh, Kohaku!” Yuzuriha gasps. “I’m so sorry, I forgot you were there!”

The others turn to stare at her. “Holy shit, you actually found someone?” Senku exclaims.

One not-so-brief conversation later, everyone’s up to date on the situation, with Senku explaining how he’d extrapolated that since their revival scars had to be healed over somehow by pulling the edges together, it would likely do the same for a snapped bone, hence his decision to draw Tsukasa’s attention to his neck. 

After that, they debate on what their next course of action should be. Kohaku is definitely willing to offer her support, but she notes that she’s not really an authority in her village, so getting more help is going to take time. On top of that, they don’t have any more saltpetre for gunpowder, and Tsukasa might come back at any time to get Sora and Taiju. 

In the end, it seems like the most logical thing to do would be to have Taiju and Sora return to Tsukasa in an attempt to slow down his smashing spree and monitor his movements. Since Tsukasa thinks Senku is dead and doesn’t know Yuzuriha exists, the two of them will go with Kohaku to her village and raise up the manpower they need to defeat Tsukasa.

It’s logical, but it’s also an extremely uncomfortable prospect. It means being separated from each other for months, perhaps even a year or two. The longest the twins have ever been apart was when they decided to spend their summers doing different study programs—Sora had been studying diseases in Mali, while Senku was off in Germany taking an engineering course. That was three months, with constant texting and video calls between the twins and their family and friends. 

Neither likes it. But it’s what needs to be done. 

“Ahh, and I just woke up too,” Yuzuriha laments as they prepare to say their goodbyes. “We’ve barely had any time together, huh…”

“Just our luck,” Sora mutters. “Aren’t you going to say anything to Taiju though?”

Yuzuriha blushes. “Sora-chan! I don’t—I hardly think this is the time!”

Sora stares at her. “How many chances are you going to get, you think?”

Yuzuriha freezes. She looks over at Taiju and Senku having a conversation a little ways away, while Kohaku is perched up in a tree looking out for danger. 

“I…” she sighs. “How about this? When I say I’ll confess when we see each other again, that’s a promise to say we will see each other again.”

Sora’s hard gaze softens. “Alright.”

The two girls hug, and then Sora goes to say goodbye to her brother.

“Chi,” Senku says in a low voice. “About the statues—“

“Way ahead of you,” Sora says. “I’ll have to test different types of rejoining on the sparrows, but I’ll figure it out.”

“Medical stuff was always your thing,” Senku nods. 

They stand in silence for a moment.

“I’ll look after Yuzuriha,” Senku says eventually. “If you’ll look after Taiju.”

“Please,” Sora rolls her eyes. “She’s going to do most of the looking out, we both know that.”

Another pause.

“No goodbyes,” Sora says eventually. 

“No goodbyes,” Senku agrees. “We’ll see you later then.”

“Yeah.” Sora says. 

“See you later.”

Sora’s quiet for a while as she and Taiju make their way along the river back towards Tokyo. A long while.

“Sora?” Taiju eventually ventures. “Are you, um…okay?” 

Sora doesn’t answer him.

“Are you upset about Senku not telling you what he was doing?” Taiju wrings his hands. “That was scary huh? But I mean…you know how Senku is sometimes, he’s worried that if he says stuff out loud then it won’t work out exactly the way he wants it to. But this time it ended up okay, right? His plan worked perfectly.”

Sora takes a deep breath. 

“He didn’t know that it would work.”

Taiju startles. “Huh?!”

“There was no way to test the hypothesis,” Sora says, voice hollow. “No way to know if the stone could pull together breaks if only part of the body was petrified, no way to know if Tsukasa would actually hit his neck in the right place.”

Her fists clench at her sides. “He didn’t tell me because he knew I’d poke holes in the plan. Because I’d stop him.”

Taiju looks down at the ground. “Oh.”

“Tch.” Sora grimaces. “He’s a gambler, my stupid excuse for a brother. The type of scientist who stretches limits and takes risks, who tries things that might not work on the off chance a miracle happens. And that’s all well and good, that’s important for progress, but I’m not the type of scientist to gamble with life.”

Taiju looks contemplative. “I don’t know that he’d see it that way.”

“Hm?”

“He chose to risk his own life, but only because he didn’t want to gamble yours,” Taiju says.

Sora blinks.

“It was the best chance he had, right? He knew you didn’t have the same patch of stone on your neck, after all. And he knew Tsukasa would want to honor his promise not to hurt you. If it was always going to happen that way, I think he made the best choice he could, and had to put faith in the idea that it would work, or he wouldn’t have the courage to do it.”

Sora frowns “It was still a really dumb idea,” she mutters, looking down. “What other shit is he going to pull without me there to balance him out, you think?”

“Yuzuriha is with him,” Taiju says. “You trust her, right?”

“Well duh,” Sora scoffs, “and I know she’s definitely capable. But—” She looks off into the distance. “…Whatever. Let’s keep going.”

She speeds forward, and Taiju frowns at her back for a second before moving to catch up.

Kohaku leads Senku and Yuzuriha to her village, where she introduces them to her friend Chrome. Well. Introduces is a strong word, since he and Senku quickly get into a competition that ends with Senku claiming Chrome’s storehouse of various rocks and plants. Then after learning that Kohaku’s sister is ill, Senku decides they’ll be working on antibiotics to prove their good intentions to the village.

“You know,” he says as he’s drawing out a flow chart in the dirt, “this kind of thing is something my sister would be great at. She’s studied diseases and medicines a bit more than I have.”

“Your sister?” Chrome asks curiously. “Where’s she?”

“We split up because of a conflict with a man named Tsukasa,” Yuzuriha explains, detailing the plan they have so far. Chrome looks astonished.

“That sounds pretty intense,” he says. “Are you sure they’ll be okay over there in the enemy village?”

“Tsukasa might be a murderer, but I think he really does believe women and girls need to be protected,” Senku says. “Besides, if there’s one man I trust with Sora’s safety, it’s Taiju. But that aside, we’ve got to pick up the slack while they’re on their own mission.”  

And so the work begins.

Senku’s usually pretty focused on the task at hand, so socializing isn’t a super big part of the next few days. Though even when they do have time to chat, he finds it’s mostly explaining modern day stuff to Chrome. Which isn’t bad by any means—Chrome is very fun to talk to, but he’s starting to wonder if Yuzuriha is actually annoyed with him for some reason. She rarely initiates conversation except when it has to do with chores or the medicine project, and she spends a lot more time chatting with Kohaku and the little girl named Suika who’s inserted herself into the group. 

At first Senku chalks it up to the fact that Yuzuriha misses Sora and wants to talk more with girls, which seems pretty normal. But then when she gets adopted by the old craftsman Kaseki, she practically vanishes as soon as Senku wakes up to go out for lessons on woodworking and glassblowing, and hardly ever mentions stuff about it to him. Even if Yuzuriha’s caught up in projects, she loves talking about stuff she learned, just like the twins. 

Senku’s not sure how to broach the subject with her. They might not be super close, but they’re still friends. And it’s hard not to care about getting along with your sister’s best friend/your best friend’s future wife. 

He’s also a bit stumped at what would make calm, sweet Yuzuriha so upset with him that she’d barely want to talk to him. Is it because she misses Sora so much that being around someone who looks so much like her hurts? She’s never been one for that sort of melodrama. Or maybe she’s angry at him for sending Sora over to Tsukasa. But no, that makes no sense either, Yuzuriha fully accepted that they were all taking big risks and she wouldn’t waste time worrying when she knows Sora can handle herself.

He finally gets his answer when they start making plans to collect sulfuric acid from a spring filled with toxic gas.

“We only need one gas mask,” he tells Chrome in the evening, while everyone else is busy elsewhere. “It’s not logical to risk both of us at the same time, so I’ll be going alone.”

Chrome stares at him in shock for a moment, but before he can say anything Yuzuriha bursts out of the shadows with the darkest look Senku’s ever seen on her face.

Chrome blinks. “Yuz—“ 

Yuzuriha storms up to Senku, glaring at him with so much intensity, he’s immediately reminded of Sora.

“Uh,” he says, right before Yuzuriha shoves him backwards and onto the dirt.  

“YOU IDIOT!” She shouts. “Are you seriously saying you plan on throwing your life away like that?!”

Senku glares at her. “Hey, I’m not planning on dying, I’m just saying me going alone is the most logical choice of action! If both Chrome and I get taken out of commission, we can’t finish the medicine!”

“You might both be taken out anyway because someone would still have to collect the acid!” Yuzuriha shoots back. “But that’s not the worst thing about all this. The worst thing is that YOU’RE DOING IT AGAIN!”

Senku’s eyes go wide. “What—“

“Do you have ANY idea what it did to Sora-chan to watch you sacrifice yourself for her?” Yuzuriha shouts. “How BROKEN she looked staring at your body?!”

Senku stares. 

Tears are falling from Yuzuriha’s eyes as her chest heaves. “Do you have any idea,” she says softly, shakily, “what you mean to her? To all of us?”

Senku opens and closes his mouth. “I—Yuzuriha—“ 

She lets out a choked sob and sinks to her knees with her head in her hands. Chrome looks at her, then at Senku.

“I think…you guys need to talk,” he says quietly, taking his leave.

When he’s out of sight, Senku slowly scoots up closer to Yuzuriha. She doesn’t look at him.

“Hey, I…” he takes a deep breath. “I’m sorry, Yuzuriha.”

She glances up at him with a sad expression, tear tracks painted on her cheeks. “I don’t think I’m the one who needs to hear that,” she says quietly. 

“There weren’t any other opt—“

“You didn’t see her,” Yuzuriha says. “Yes, it all worked out okay. But you didn’t see the light leave her eyes when we thought the revival fluid hadn’t fixed you, when we thought we lost you for good. You didn’t hear her, the way she begged you to come back. And I know she didn’t tell you, because she’s too proud for her own good, and you’re too afraid of feelings to ask. You probably didn’t even think about it, seeing as you’re planning another risky venture like this.”

Senku blinks. “…We still need the acid.”

Yuzuriha shakes her head. “This time, you have to put your trust in the fact that you’re on a team, instead of making decisions for everyone and hurting them because of it. Let Chrome help. Let me help. Tell us what you’re thinking. Trust us.”

Senku is silent for a moment. Then, he nods.

“Okay. Okay, I’ll do that.”

They sit like that for a while, and then Senku speaks again. “This is what you were mad at me about this whole time, huh?”

Yuzuriha tugs at her scarf self-consciously. “You broke my best friend’s heart, Senku-kun.”

“I know.” Senku takes a deep breath. “I’ll apologize properly, when we see her again.”

“Okay.” She lets out a shaky exhale.

“Okay.”

Things are better after that. Chrome and Ginro help Senku retrieve the sulfuric acid, and no one is hurt. That said, Suika tells Senku that the whole time they were gone Yuzuriha was as tense as a wound up coil, and didn’t relax until she heard they’d all return safe and sound.

After that, Senku goes up to her, and Yuzuriha suddenly hugs him.

“Thanks for coming back,” she says quietly.

He pats her shoulder. “Thanks for trusting me to come back.”

 Senku thinks Yuzuriha might not actually fully forgive him until he apologizes to Sora, but at least they’re talking more like they used to. Sometimes they’ll sit outside Chrome’s hut together by the fire and chat quietly about things from the 21st century or memories of schooldays past. The villagers are great friends, but it’s nice to have someone to talk to who understands what a tv show is. 

Eventually, she sheepishly asks if she can brush his hair. When he gives her a look, she blushes and looks off to the side. 

“I miss doing Sora-chan’s hair,” she admits. “Kohaku’s always busy training and doesn’t do anything with hers, and Suika’s isn’t as long as yours…”

Senku sighs. “Fine.”

Actually, it’s not that bad—it’s relaxing, even. Yuzuriha will put his hair up in a variety of braids and then take it out again after she’s done, or just mess around with it like a green mop doll.

He decides it’s only fair to brush hers in return, and is immediately shocked when the brush slides through far easily than it had through his own hair. This prompts a conversation about genetics and physics, and Senku thinks that maybe he’s starting to see why his sister likes Yuzuriha so much.

 It’s nice, to be with a friend in this strange, often scary new world.

He thinks Taiju and Sora would agree. 

Things are rough at the start. Sora knew to expect it, knew she’d be set with the challenge of keeping her temper under control while talking to the man who killed her brother, but it’s even worse than she could have imagined.

When they finally get back to Tsukasa, it’s Taiju who has to do the talking, because Sora’s standing behind him with her fists clenched and eyes firmly fixed on the ground. Tsukasa, true to his word, welcomes them with open arms, and even says he understands they’re still grieving and offers them a cave room in the weird mountain-thing he’s claimed that’s far from his own, so Sora doesn’t have to see him too often. He’ll communicate mostly with Taiju, and vice versa.

Tsukasa leaves them to go locate the first person he wants to revive, and once he’s out of earshot Sora lets out a strangled scream and moves to punch the stone wall, before Taiju grabs her wrist.  

“I hate him,” Sora hisses. “I hate him I hate him I hate him!”

“I know,” Taiju says quietly. “Come on, let’s get some furs for our bedding.”

Tsukasa brings back a statue of a woman, and asks Sora—well, he asks Taiju to ask Sora—to sew her some clothes. Sora’s initially confused—she didn’t think Tsukasa had a girlfriend—but they soon find out that she’s actually a reporter who Tsukasa thinks can help him locate some useful people to help build up the settlement.

Her name is Minami, and she’s a big fan of Tsukasa’s wrestling career. This also means that Sora instantly hates her guts, and within a few minutes of meeting Minami Sora stomps off to her and Taiju’s cave to angrily stab leather with a needle ten million more times. 

Tsukasa revives more and more people, mostly other wrestlers or athletes Minami knows. At least, that’s what Taiju tells her. Because Sora spends most of her time sewing clothes in the cave—they bring her statues, she crafts the outfits, they take the statues away. She’s not half as good as Yuzuriha, but her work is passable, and nobody else knows how to sew. Her best friend would be scandalized at the idea of reviving so many people with so few textiles skills. 

Taiju’s often pretty busy himself, but every night without fail he returns to the cave and tells Sora about what he did that day, the people he talked to and where Tsukasa was seen going off to smash statues.

This is the critical information. Once she confirms where Tsukasa’s been, Sora will sneak out alone, collecting the fragments of statues and transporting them to another cave, hidden carefully where few people would even think to go. 

It’s agonizingly slow, collecting all the pieces, and Sora’s not skilled enough to put them back together, nor does she have enough time with Tsukasa constantly demanding outfits for new revivals. Oh, and some of the idiots are careless and tend to damage their clothes, so she has mending and even first aid to deal with.

Her and Taiju’s room becomes something of an apothecary, with jars of poultices lining the walls and bundles of herbs hanging up here and there. People come to her for all sorts of things—aches, pains, cuts, bruises, that kind of stuff. She always handles it with a curt, clipped voice, her patience sapped by just being there.

The first time someone actually gives her shit for it, Sora snaps and tells the man that if he wants to die of infection he can be her guest, and he storms off after calling her a witch (and also something that rhymed with it). Later, he returns looking mollified and apologizes, asking if she would please try again.

From what Taiju tells her, the man had complained to Tsukasa, along with several other folks who didn’t like Sora’s bedside manner. Tsukasa had told them all off for disrespecting Sora, and that they should be grateful for her help.

Sora doesn’t hate Tsukasa any less, but at least people aren’t bothering her as much. Aside from the aggressive types, there’s also the nervous types, who seem to think of her as some sort of creepy hermit they’re afraid of, and the friendly types, who try to get to know her. They tend to quickly turn into the nervous types when Sora refuses to answer them with more than two words at a time though.

There are a few people however who stand out, and those are the quiet types. The kind of people who come in and go out without saying hardly anything except for what they’re there for, and actually make Sora nervous.

There’s only three of them. Saionji Ukyo, Momiji Homura, and Akatsuki Hyoga. Sora knows their names because she keeps a record of who needed what treatment and stuff in a ledger, and so she can track potential contagious illnesses, repeat injuries, and her stock of herbs. They’re all eerily quiet when they meet with her, and she’s not sure what to make of that.

But then Taiju reveals something interesting to her one night. Apparently Ukyo had approached him and asked about how he and Sora had joined up with Tsukasa, seeing as Minami had no idea who either of them were, and they’d been awake before her besides.

Taiju had told him that Sora and her twin brother Senku developed the revival formula, which seemed to surprise Ukyo since Sora is only involved with revivals by way of sewing clothes for them. When asked what happened to Senku, Taiju only said “he’s not here anymore,” and left before Ukyo could press further.

“Do you think we should tell people?” Taiju asks Sora. It’s late at night, and Sora is letting some herbs and honey cook together over the fire. “That he killed Senku?”

“Honestly, I don’t know,” Sora admits with a sigh. Something about how earnest Taiju always is and how much she holds back her emotions in front of everyone else makes her too tired to be sarcastic at the end of the day. “Tsukasa is charismatic. He’d say it was for the greater good and they’d believe him. So what’d be the point of us talking about it?”

“I don’t think everyone would believe it,” Taiju says. “Some people here are pretty nice, actually. I don’t think they’d be okay with murder even if they learned it was someone they trusted.”

“You say that, but you don’t really know,” Sora says tiredly, ladleing the honey into a jar and sealing it over with beeswax-coated paper bark. “Lots of people seem totally okay with the statue smashing, right?”

“…Yeah, some.” Taiju fiddles with the edge of his blanket. “You’ve been really tired lately.”

“And the sky is blue,” Sora mutters. 

“Do you want to talk about it?”

“What is there to say? There’s not a lot to be done other than keep going,” Sora says. She puts out the fire. “Goodnight, Taiju.”

“…Goodnight.”

The next day however Taiju returns surprisingly early, around noon, and excitedly runs up to Sora.

“I got us the day off! Come on!”

“Wha—?!” Taiju drags Sora out of the cave and down the side of the hill, “How did you—?!”

“I told Minami you were really tired and worn out, and she talked to Tsukasa and Nikki, and they said it was okay since we need our doctor in top shape! So come on!”

“Where are we going?!”

To the beach, apparently. Taiju lets go of Sora’s hand and runs into the water, laughing as the fish swirl around his ankles. 

“Taiju, you—“

SPLASH!!

Sora blinks. Freezing cold water is dripping down her face. Taiju blinks.

“Um! Sorry!”

Sora stares at him. And then.

She laughs.

Sora runs into the water, not even caring that her skirt gets soaked. She kicks at Taiju, splashing his side. He yelps and splashes her back, and they laugh until their sides hurt and they collapse on the sun-warmed sand. It gets in Sora’s hair and mouth, but she can hardly bring herself to care.

“Do you remember,” she says suddenly, “When we built that castle that was so big you could park a car in it?”

“Do you mean the one with the drawbridge or the one where you brought the nerf guns to make the battlements?” Taiju asks.

“The one from the time Sen got bit by that turtle.”

“Oh yeah! That was fun.”

They lie there for a while, talking about their childhood, about their favorite adventures. The tension in Sora’s chest loosens, and she feels like she can breathe properly for the first time in months.

Taiju is Senku’s best friend, not hers. But Sora’s learned that he has a lot of love to give, and seemingly no distinction for who he gives it to. Sometimes that can seem like a weakness, and she’s worried he’s too trusting, too kind.

But maybe he’s right sometimes. Maybe he’s just kind enough. 

“Taiju?”

“Hm?”

“Thanks.”