Chapter Text
“Here, Mui, see if you can fit in here.”
Yuichiro sat back to observe his handiwork. With Kyojuro’s help, they had fashioned together a tightly woven basket using the wood and bamboo stalks scattered around the house. They would need some way for Muichiro to travel during the daytime, and this basket was their best option.
Still, Yuichiro couldn’t help but think the basket looked somewhat small. He and his brother weren’t big by any definition, but he wondered if Muichiro could really fit comfortably inside. He watched as his younger twin stared blankly at the basket for several seconds before crawling inside. It definitely didn’t look comfortable with how scrunched in he was, but somehow, he did fit, and Kyojuro was able to close the lid over him.
“Are you sure you don’t wish for me to carry him, Tokito?” Kyojuro asked, now back to that annoyingly loud and chipper tone of voice. “It would be quite easy for me!”
“Hell no! You were going to cut off his head an hour ago!” Yuichiro snapped. “I’m his brother; I’m carrying him!”
Without waiting for a response, Yuichiro grabbed the straps of the basket and hefted it into the air. Except where he expected the weight of his twin to be, there was next to nothing, and Yuichiro stumbled off-balance. But before he could hit the ground, he felt a pair of calloused hands grab him and hold him up.
Kyojuro grinned down at him. “You should be more careful, Tokito!”
Once the moment of shock passed, Yuichiro felt his face heat up from pure fury. “L-Let go of me, you stupid owl face!”
“You are welcome!”
“I didn’t- agh!” Yuichiro couldn’t tell if he was being messed with or if the slayer was genuinely this dense. He freed himself from Kyojuro’s grasp and looked at Muichiro’s basket in his hand. It still felt like he was holding only the basket with nothing inside.
“Um, Mui, you in there?”
“…Yeah.” His twin’s voice was unmistakable, and he sighed in relief. Still, he remained confused. Was this a demon thing? He’d heard demons could change their forms; could they make themselves lighter, too? He considered asking Kyojuro, then remembered his previous anger and decided not to.
“Are you ready?” Amane asked from near the doorway. “It would be best to leave while we still have hours of daylight remaining.”
Yuichiro’s anger was doused by a sudden somberness. He looked around the house one last time; small and rundown as it was, it was still home. Their parents’ graves were here, and all their memories, too. But just as the nostalgia was starting to get the better of him, Yuichiro remembered himself and shook his head in disgust. He and his brother had nothing to gain from such sentimentality; better to leave now before they made it any harder on themselves.
The boy nodded and slipped the basket onto his back. Though it was still unbelievably light, he could feel his twin’s presence within. It gave him comfort, and the strength of will he needed. “Yeah, let’s go.”
Yuichiro stepped into the sunlight, and for a moment he felt worry, that the basket wasn’t knit tight enough, that the sun would reach his brother. But Muichiro remained calm behind him, and Yuichiro let out a breath he didn’t know he’d been holding.
With Amane and Kyojuro behind him, Yuichiro refused to look back as he and Muichiro left their childhood home for the final time.
—
“How far are we going, anyway?”
Yuichiro wasn’t sure how long they’d been walking. He’d estimated they left in the late afternoon, but now the sun was setting, painting the sky shades of yellow and orange. All he could tell was that they were almost off the mountain. And while there was a village at the base of the mountain, he doubted the Ubuyashiki Estate was there. They were going in the wrong direction for that, anyway.
Exhaustion was slowly but surely creeping up at him as he voiced his question. He was in no way surprised that Kyojuro was still going strong, but he couldn’t fathom how Amane was still walking so gracefully in such fancy clothes. He wished he could at least talk to Muichiro, break up the monotony of travel, but his brother seemed to have fallen asleep or something. Only the feeling of his presence assured him he was still there.
“We won’t be able to reach the estate before nightfall, so we’ll be staying at one of the corps’ rest stops tonight. Don’t worry though, It’s not much farther.” Amane explained.
Yuichiro nodded and kept walking; no use in wasting energy complaining. After about ten more minutes of travel, Amane stopped. “We’re here.”
Yuichiro peered around her, and his eyes widened at the sight of a large wooden building amongst the trees. He had lived on this mountain his whole life, and never once knew this was here. Compared to his own home, it was like a mansion. The image of a wisteria flower adorned the doorway to what he guessed was an inn.
“Quickly now, before night falls!” Kyojuro ushered him in. Yuichiro didn’t need to be told twice, eager to finally rest after such an exhausting day.
The staff were already waiting at the entrance, clearly expecting their arrival. Within minutes, all four of them were settled in a cozy bedroom. Their caretakers closed the sliding door with a click, and once he was sure they were gone, Yuichiro removed the basket from his back and set it on the ground.
“Alright Mui, it’s safe to come out now.”
He started to open the lid as he spoke, but as he did, a tendril of wispy white fog escaped through the gap he’d created. Yuichiro froze, not quite comprehending what he was seeing, and in that time, the misty tendril retreated back into the basket. A second later the lid popped off as Muichiro sprang up with an annoyed grunt.
Yuichiro blinked and decided whatever that was, it wasn’t worth worrying about now. “How are you feeling?”
“…Hungry,” he said bluntly.
Mortified, Yuichiro sprang up and punched his twin in the arm. “Don’t say that in front of the demon slayers, stupid!”
Muichiro didn’t seem bothered by the punch and merely sat down on the floor. He stared silently at Kyojuro, who stared back quizzically. He was still smiling though.
What a weirdo.
“Muichiro does seem quite different from other demons,” Kyojuro observed. “He's quite strange, in fact! Why is that?”
“If I knew that, I’d tell you. He just is.” Yuichiro paused, then added with a glare, "Different, I mean. Not strange."
“Perhaps you’d be willing to tell us what happened the night your brother was turned?” the Hashira suggested. “It may provide us with answers.”
Yuichiro scoffed and sat down next to his twin. “I doubt it, I barely know anything myself. When we were attacked, I got injured and couldn’t move. I think Muichiro fought the demon, but by the time I saw him again, he was already turned. But I'm pretty sure the demon that attacked us and the demon who turned Muichiro aren't the same.”
He didn't mention the dream, nor the mysterious thing he’d seen Muichiro eating before he blacked out. He still vividly remembered waking back up in the house with those glowing eyes peering at him from the darkness. He’s not proud of how loud he had screamed.
“You believe there were two demons there that night?” Kyojuro asked.
Yuichiro nodded and turned to his brother, waiting for him to speak. But Muichiro looked hesitant, so after a moment, he reached over and took his brother’s hand in his own. Empty turquoise eyes widened ever so slightly in response.
“Come on, Mui, tell them what you saw.”
“…Six eyes…” Muichiro fell silent after that. Kyojuro seemed to expect him to elaborate, but when he didn’t, his smile fell.
“Is that all?”
Muichiro nodded, and Kyojuro looked thoughtful. “‘Six eyes’ must refer to the demon. Perhaps it is indeed an Upper Moon?”
“Why do you think that?” Yuichiro couldn’t help but ask. “What is an Upper Moon, anyway?”
“The Upper Moons are the six strongest demons under the command of the demon king, Muzan Kibutsuji. Only Kibutsuji, or the Upper Moons who possess his blood, have the power to turn a human into a demon. This also supports there being two demons, since if an Upper Moon attacked you with the intent to kill, you would not be alive right now. Young Muichiro, was there a number in the demon’s eyes?”
Yuichiro was going to chide him for trying to force answers his brother didn’t have, but then Muichiro nodded. His jaw dropped as Muichiro lifted up a hand and, after much deliberation, slowly raised up a single clawed finger.
“Upper… One.”
Kyojuro’s eyes went wide. Yuichiro looked to him for answers, but surprisingly, it was Amane who spoke instead.
“Upper Moon One. That would be the strongest of the Upper Moons, and the most powerful demon behind Kibutsuji himself.”
“Wha- You’re kidding, right? You’re saying we were attacked by a demon that strong?! Why?!” Yuichiro couldn’t believe it. The second most powerful demon? Why would someone like that be wandering around their mountain? He couldn't imagine how they were even still alive at this point. And why would Upper Moon One turn his brother into a demon in the first place?
“Why, indeed?” Kyojuro seemed to have recovered from his shock. He put back on that ill-fitting smile. “Unfortunately, we do not know! Still, you are lucky to have survived such an experience!”
Yuichiro scowled. It seemed the only person who would know would be the Upper Moon itself, but the idea of going after someone like that for answers was pure insanity. Well, there was nothing to be gained from looking to the past now, so Yuichiro turned his thoughts to the near future. “…What’s going to happen once we get to the Estate?”
“To Muichiro, you mean?” Kyojuro asked, and he nodded. “That is for the master to decide. Whether he vouches for your brother’s safety or not, no demon slayer would dare to go against his word.”
Yuichiro thought that this master must be someone quite fearsome if all the slayers followed his word without question. But it was only by the master’s words that his brother was still alive now, so he prayed that his mercy would remain once he saw the truth.
“Forgive me for interrupting,” Amane spoke. She had sat by the window all this time, and a crow was perched on her hand. “But I should inform you that we are expecting visitors soon.”
“Huh? Visitors?” Yuichiro repeated. A glance at Kyojuro showed that he was just as confused.
“Visitors? Who might that be?”
“I cannot explain at this time, but do not be alarmed. Master Ubuyashiki has been informed of your situation, and this is a necessary step before we can depart for the manor. They should be here within two nights, so we will remain here until then.”
Yuichiro balked at that. Two nights? They were gonna be stuck here for that long? This manor was a nice place, certainly much nicer than his own home, but still! He didn’t want to be with these people any longer than he had to!
Muichiro’s grip on his hand tightened, bringing him back to the moment. Yuichiro hadn’t even realized he was still holding onto him. “Don’t…worry. Will be… okay.”
A moment of silence passed, Yuichiro realized his breathing and racing heartbeat were slowing. He squeezed Muichiro’s hand back. “Yeah, it’ll be okay…”
He wished he could believe that.
—
It was on their second night in the Wysteria Inn when their mysterious visitors arrived. Yuichiro was thoroughly bored. He'd already changed his bandages and finished his nightly routine, so now he was listlessly watching his brother as he engaged in a staring contest with Kyojuro. Well, sort of, as Kyojuro was blinking quite frequently, shaking his head every few seconds before going right back to staring.
“You should probably stop doing that,” Yuichiro told him. “You’ll damage your brain or something.” Then again, the man was already so strange that it likely wouldn’t make any difference.
“Ah! Then you’ve noticed it as well?” The slayer asked.
Yuichiro nodded. How could he not? He’d realized quickly that gazing into his brother’s demonized eyes had a strange effect. Every time he stared for too long, he’d find his mind clouding over, his thoughts and movements slowed. It was unnerving, so he tried to avoid it as much as he could.
“It is certainly a Blood Demon Art! To hinder an opponent’s thoughts and reactions with mere eye contact! What a fearsome ability!” Kyojuro sounded impressed. “I must do my best to develop a resistance to it!”
Yuichiro glared; did he think that he might have to fight Muichiro in the future? “He’s not doing it on purpose.”
“I understand! There are many examples of passive Blood Demon Arts such as this!”
Yuichiro sighed and continued idly watching his brother. More specifically, he watched the way Muichiro’s long hair lazily floated and fluttered in an unfelt wind. It was just something it did every so often since becoming a demon. “…Is that a Blood Demon Art, too?”
Kyojuro opened his mouth, only to stop as a voice spoke from behind the sliding door.
“Lady Ubuyashiki, your guests have arrived.”
“Please let them in,” Amane ordered, setting the book she’d been reading aside.
The door opened, and Muichiro started to growl. Yuichiro quickly reached out and took his hand to try and keep him calm. Kyojuro also looked on edge suddenly, hand gripping his sheathed blade.
Yuichiro didn’t understand the reason why until he looked at their guests himself. Standing at the door were a woman in a flowery kimono and a young blue-haired boy. They looked normal at first glance, but something about them felt off. It was the same sort of feeling he got looking at Muichiro, of something that seemed human but wasn’t. Then, were these…?
“Good evening,” the woman bowed. “My name is Tamayo, and I am a doctor. This is my assistant, Yushiro.”
The boy, Yushiro, gave an unfriendly grunt of acknowledgement as he warily surveyed the room. Kyojuro looked confused but still on guard. “A doctor? But you are-”
“Demons, yes. But I assure you, we mean you no harm.” Tamayo explained. “Master Ubuyashiki and Lady Amane requested our assistance in regards to the Tokitos’ situation.”
“Huh? What do you-”
“It is true,” Amane interrupted, causing Yuichiro to fall silent. “Master Ubuyashiki and Lady Tamayo have been in contact for a long while now. Like us, she is also opposed to Kibutsuji.”
“What? Is this true?!” Kyojuro looked shocked.
Tamayo nodded. Her eyes narrowed, a barely contained anger lining her words. “It is; I despise that man, that monster, for what he has done. I have spent centuries searching for a way to defeat him once and for all.”
“Wait, what do you mean you’re here about our “situation”?” Yuichiro asked with a suspicious glare.
“Well, as I’ve said, I am a doctor, and I’ve conducted extensive research into demons over many years,” Tamayo explained as she stepped forward and knelt down in front of the twins. “You are Yuichiro, I presume?”
He nodded. “Yeah, I am. And this is…”
He stopped as he caught sight of the expression on Muichiro’s face. He was staring at Tamayo with an intense focus, unblinking. His mouth was set in a hard grimace that showed his fangs and his body was tense and trembling. Yuichiro couldn’t help a sudden feeling of worry; his brother looked like he was in pain. “Um, Mui?”
Yushiro’s slitted eyes narrowed as he put a hand between Tamayo and Muichiro. “Lady Tamayo, you shouldn’t be so close. This one doesn’t seem-”
Muichiro's irises shrunk before he snarled and lunged forward, sinking his teeth into Yushiro’s hand.
“Gah! Get off, you mangy-!” The demon boy yelled and tried to shake him off. Muichiro responded by growling and biting even harder, earning another string of yelling and insults.
“Mui!” Yuichiro shouted in alarm. He looked to Kyojuro for some kind of help or guidance, but the Hashira looked just as lost, his sword half drawn. Clearly the sight of a demon attacking another demon was not a common occurrence. Amane also seemed surprised, but she wasn't a fighter, so it’s not like he could expect her to do anything, anyway.
A ripping sound brought his attention back to his brother, and he almost fainted at the sight of the severed hand held in Muichiro’s mouth, bone exposed and still dripping blood. Yushiro held the stump of his hand and let out a string of curses Yuichiro had never even heard of before now. It was clear that he was more indignant than actually in pain over being attacked, and Yuichiro might have even found it funny if he wasn’t so horrified by the fact that his brother had just ripped someone’s hand off.
“Muichiro!” Yuichiro finally found his voice again. “You drop that right now!”
Muichiro growled in response, and Yuichiro’s temper flared up. “Don’t you growl at me! You listen to me and drop that hand right this instant!”
Did he really just say that? But this whole situation was absurd. To think that a week ago, their lives had been normal. Miserable, but normal. And now here he was, scolding his demonized twin like a misbehaving dog to let go of a severed hand. Was this the gods’ idea of a sick joke? Tears pricked at the corner of his eyes. Why? Why did nothing ever go right for them? What god had they angered to deserve this?
Muichiro’s growling stopped. The hand fell from his mouth and landed on the floor with a dull thud, along with a couple drops of water. Yuichiro looked up and blinked away the tears to see Muichiro crying himself, tears falling freely from his eyes.
“Sorry…” he muttered, hanging his head. “Sorry…”
“…It’s okay. It’s not your fault,” Yuichiro squeezed his hand for assurance. This was all the fault of that damned demon that turned him, the one with six eyes. Anger burned in his chest at the demon that dared to make his brother cry. But as he calmed down, he began to worry for Muichiro's safety. If he attacked that boy, then was there a chance he'd attack humans? Would he have to be killed after all? Yuichiro couldn't bear the thought.
Muichiro let out a hum. His clawed hand picked up Yushiro’s severed one, and he timidly held it out to the boy in question. “Here… sorry…”
Yushiro turned away with an indignant glare. “Keep it, your saliva’s all over it now. Besides, I’ve already grown a new one.”
It was true, the demon boy’s stump had almost completely reformed into an entirely new hand, muscle and skin growing over the bones of his fingers. Yuichiro was both fascinated and a little sickened by the sight.
“How interesting…” Tamayo finally spoke up. She’d been silent throughout the entire affair, simply observing. She moved closer to Muichiro, who shrank back nervously. “Don’t be scared, I just want to ask you some questions. What have you eaten since becoming a demon?”
“…Birds, rabbits…” It seemed like there was something else he wanted to say, but he hesitated and fell silent. Tamayo smiled kindly.
“Have you eaten any humans?”
Muichiro quickly shook his head.
“Then, have you eaten any demons?”
There was another moment of hesitation, and then Muichiro nodded.
“Huh? When did you do that?” Yuichiro asked. It’s not like demons were common on their mountain, and Yuichiro had spent every night alongside his brother since his transformation. If he’d left somewhere in the middle of the night, he’d know. Unless…
“…First night,” Muichiro answered slowly. “Woke up… eating…”
The first night; suddenly it made sense. The thing he’d been eating in the dream. That black thing in his mouth; it’d been the arm of the demon that attacked them.
“How can that be?” Kyojuro spoke up. “Demons do not hunt other demons, at least not when human prey is readily available. It is not in their nature.”
“I already told you, Mui’s different from other demons,” Yuichiro retorted. He felt relieved that given the choice between eating him or the demon, Muichiro had chosen the demon. He felt pride, too; his brother’s kind heart hadn’t been extinguished by his transformation.
“It would seem so. Perhaps after your brother turned, the first thing he ate was demon flesh. If he hasn’t eaten human flesh then, he simply might not have the taste for it. Perhaps that has helped him to resist attacking humans.” Tamayo said thoughtfully.
Yuichiro nodded; that made enough sense. “Is that why he attacked that guy, then?”
Tamayo nodded. “I suspect he’s quite hungry, if he’s only been eating animals up to this point.”
Yuichiro figured as much, though he still couldn’t help feeling guilty at the thought. Logically, he knew there wasn’t anything he could do about it, but he never wanted his little brother to go hungry.
Tamayo reached into a bag at her side and pulled out an empty syringe. She edged closer to Muichiro, who stayed put this time, and spoke in a gentle voice. “I’m going to draw some of your blood for my research. Is that okay, Muichiro?”
His brother nodded, and he didn’t even flinch as the needle entered his skin. Once Tamayo had filled the syringe, she set it aside and took out another small syringe with a red liquid inside. When she looked at Muichiro again, their eyes met. Her calm smile fell into a frown, and she hummed.
“What is it?” Yuichiro couldn’t help but ask.
“How curious; Kibutsuji’s curse is weak within you.” She spoke more to his brother than to him. “An effect of your bloodline, perhaps? I understand you are descendants of the First Breathing users?”
Yuichiro rolled his eyes. Did everyone know about that? “What does that matter? And what’s this curse you’re talking about?”
“Perhaps it matters more than you think. If you are truly descendants of that man…” Tamayo paused, then shook her head. “No, it’s too soon to say. My apologies.”
Yuichiro really wanted to know what the hell she meant by that, but it was clear that Tamayo was done talking about it.
“As for the curse, Kibutsuji has a connection with all of his demons. He can see through their eyes and hear their thoughts, even control them to an extent. Ubuyashiki requested our aid to remove this curse before bringing you two to his estate.” Tamayo readied the syringe as she explained. “It seems the task is already half done, but this medicine will help as well. Is that okay, Muichiro?”
His brother nodded again. Yuichiro reluctantly allowed her to continue, but he still watched vigilantly as Tamayo administered the medicine. Muichiro still didn’t react in the slightest as the needle pierced his arm, but seconds after the liquid was pushed in, his eyes started to drift shut. He wobbled, and Yuichiro reached forward to catch him before he fell over. Panic rose briefly before he realized that his twin had only fallen asleep.
“Do not worry, he’ll simply need to rest for a few hours while the medicine takes effect,” the demon doctor explained. “In the meantime, we must take our leave.”
“Oh? So soon?” Kyojuro asked, voicing Yuichiro’s thoughts. Not that he really cared whether they stayed or not.
“My apologies, but while traveling like this, we don’t have our usual defenses against Kibutsuji’s detection. We wouldn’t want to put you in danger.”
“Fear not, Lady Tamayo! I will handle any demons that dare to come here!”
“Thank you for your assistance, Tamayo,” Amane bowed her head gratefully.
“I am happy to help. A demon who does not attack humans… Such a thing is almost unheard of. But it gives me hope that…” She stopped and stared almost wistfully at Muichiro, then turned to leave, Yushiro right behind her.
“Wait!” Yuichiro called before she could go, a desperate question suddenly springing to life in his mind. “Can… Can a demon be turned back into a human?!”
If anyone would know, it would have to be her, right? This doctor who researched demons? Tamayo looked surprised for a moment, then contemplative.
“…There… may be a way.”
For the first time in a long time, Yuichiro felt hope.