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Chapter Text

Adrenaline coursed through his veins as white hot anger shot through him.

He glared at the demon before him. This was the one that killed Sabito and Makomo, the two that had trained him, perfected his technique, and were probably the only reason he’d passed Urokodaki’s trial.

The demon that killed his friends.

Memories flashed by him. Makomo's soft smile and kind eyes as she perfected his form, reassuring him every step of the way despite being as harsh a teacher as Urokodaki. Kind, sweet, and always striving to help him improve. She was smart as a fox, too. Her every piece of advice coming in handy in his next match against Sabito. And then there was Sabito's harsh exterior that was complimented with his deeply caring personality. Even after he'd kicked him down a hundred times, he never criticized him more than his mistakes, focusing entirely on what he'd need to improve rather than pointing out how far he still needed to go. Building him up, even when he felt like he'd just crumble down. And he always accepted his rematch, going back into the fray with a ferocious spirit that was infectious.. And the smile that took over his face when Tanjirou finally won, his soft features overtaken with pride at him finally being bested. They had talked with him, worked with him, sometimes they even hung out with him. Just for fun. Just like they were regular teenagers, and not two ghost and someone who'd lost everything.

He'd bring them food when he noticed them skipping meals. He thought they just didn't have good eating habits and wanted to help them the same way they helped him. He'd even brought them some things from the town as gifts to show his gratitude. They were his friends. He could almost convince himself they were his siblings.

And this demon killed them.

He couldn’t let it live. Makomo’s words floated by him, the reminder to not lose himself in anger, lest he meet his own end, but the warnings felt muted. It was hard to think, and even the thought of her kind eyes filled him with rage at the being that had ended her life too soon.

They would be avenged. He would make sure of that.

The Hand Demon laughed as he recounted their deaths, finding infinite amusement in their struggle before their end. Tanjirou gripped his sword tightly, blood thrumming through his veins, muscles coiling like a spring as he took a breath.

He interrupted the demons mad ravings, shouting “You bastard! You’ll pay for what you did to them!” As he sprang forward, rushing the demon as quickly as his muscles allowed.

The Hand Demon retaliated with a sadistic giggle, launching a barrage of hands that stretched towards him.

With practiced ease, Tanjirou ducked and dodged, slicing the arms into ribbons as he darted across the battlefield. He moved quick, flowing like water just as he was taught, leaping at an opening to make headway towards his target.

He gritted his teeth as he pivoted on his feet, narrowly avoiding a grab that threatened to crush his skull. He brought his sword to bear and severed the offending limb before bursting forward again towards the Hand Demon, who only seemed delighted by his actions.

He was so focussed on his target, he didn’t see the fist coming until it was too late. It caught him on his side, slamming into him with so much force that the air was forced from his lungs. He felt ribs crack as he was flung to the side.

He hit the tree hard, head swimming as he collapsed to the ground. His entire body hurt like all hell, making nausea well up within him, but he held it down as ye fought the blurriness consuming his vision.

Chapter Text

Tanjirou didn't want to let go. He didn't think any of them wanted to. But eventually, even the tears of the dead ran dry, and they slowly began to pull themselves together. He did mean slowly, as the spirits clutched at one another for a full half hour before any of them were ready to move.

Tanjirou didn't know what this meant. He was dead. He saw his body, his mutilated corpse that couldn't possibly sustain life, head reduced to a bloody stump. He saw that mutilated corpse being eaten in front of him. He watched as his own blood dripped from the maw of that filthy demon. Yet here he stood.

He felt numb. Cold. Dead.

He reached for his arm, feeling for a pulse. There was none. He went for his chest, feeling for the rhythmic beat of his heart. It was silent. He reached for his jugular, feeling for the thrum of life that had been omnipresent since the day he was born. It was gone. He was gone.

Yet for that brief moment, as he lined up to strike, he'd felt real. The demon had seen him. And clearly, it felt him when his blade severed its neck and separated its head from its body. The question was, how? How did he do it? Where did he go from here? And what did he do now?

He was dead, sure. But did that mean he had to give up? He killed the Hand Demon; maybe he could do it again, with more demons. Maybe he could even cure Nezuko! There was so much he needed to do before he could allow himself to rest.

His sword lay heavy in its sheath, its weight steadfast. Did... Would anyone even be able to tell? Tell he wasn't alive? That he was a ghost? He couldn't tell Sabito and Makomo were dead until the Hand Demon had proclaimed them so, it was possible he could pass for normal. He could still do the final selection. He could make it back to Urokodaki, and let him believe he'd made it back alive. He could defeat the demon who'd killed his family, even if it was possibly his last action on this plane. He wasn't done yet. He... could still fight!

"Hey Tanjirou, you coming?" A boy, Hinata, asked. He made his way over from the group to stand next to him. "We can finally head back home! I wanna show you my favorite spot on the mountain before... we move on? Honestly, I have so many questions about how long we'll stay as ghosts, but I want to make the most of it with you!" He said eagerly.

"I think I'll stick around for a bit," Tanjirou replied. "I still want to finish this. And there are some things I need to figure out, too."

"Oh... Oh!" Hinata sighed before brightening. "I get it! You wanna see if you can do that thing you did to the Hand Demon again!"

"Got it in one!" He smiled softly, ruffling the boys hair. He gave an encouraging grin, radiating energy. "I'm not done yet! I wanna keep fighting! If I can still help, I'll help! But, I promise I'll be back, okay?"

Hinata looked up at him with stars in his eyes. "You're so cool Tanjirou! Alright, I'll see ya ahead! Go get em!" He said excitedly, before turning to run back to the mists. The other students gave him waves and smiles before turning to head home. Back to Mt. Sagiri. Back to Urokodaki.

He watched them go, with mixed emotions swirling in his gut. If this didn't work, he'd have to join them. And he wasn't ready for that yet. His clock couldn't run out now. Not yet. He refused! He still had so much left to give. Nezuko would be human again. He'd make sure of that.

He turned into the forest and headed out into the night. He didn't really know where to start, so he just focused on his breathing, trying to feel anything within him like he did in his charge against the Hand Demon. Again, he noticed his footsteps made no sound, and he passed through the foliage without a trace. Pausing, he lifted a hand and nearly threw up when he phased it through a tree. It was another sickening reminder he was dead.

He breathed deeply, allowing the air to flow through his lungs like Urokodaki had taught him. He could feel something almost out of reach on the edge of his consciousness, and he grabbed at it, pulling it closer.

He heard a twig snap beneath him. 

He raised a hand again and felt the wood solid under his touch. Unconsciously, the feeling slipped through his fingers, and his hand faded. He... He did it. He did it!

He let out a whoop of joy without meaning to, enjoying the feeling of air on his skin he didn't even realize he was missing. There was just an overwhelming sense of numbness earlier; the other kids were the only things he could truly feel, but now he felt everything again, and he reveled in it. He pulled the fox mask over his face, feeling the cool wood press against his features, smelling the scent of oak and paint that reminded him of Urokodaki. He smiled into the mask, before running off into the forest feeling better than he'd felt in a long while.

He almost laughed in delight when a demon rushed him. It meant he was visible, that he was real. He ducked its punch and whipped out his sword, cutting the creature's head off with a calculated slash. He was real. He may be dead, but he was real! He didn't realize how much it meant to him until he stared out over the demons' thrashing remains.

He almost didn't hear a second one running up behind him. In his panic, that feeling of connection within him loosened, and he stopped feeling the wind on his skin. The demon brought its fist down on his skull in a blow that would have killed him, but it passed harmlessly through. If he'd been breathing, he'd have gasped in surprise. The demon certainly did.

"I- you- HOW!?" It yelled, swinging again, only to phase through once more. Tanjirou's wits came back just in time for him to pull himself together and swing for the exposed neck; the demon fell down dead. 

He leant down to the demon's decaying head and whispered. "Sorry, but don't you know? You can't kill a ghost." Placing one finger over his mouth in a shushing motion, he fully relaxed and felt himself fade fully, turning to mist before the demons eyes. The demon's eyes widened in horror before he fully fell away as dust. He had to stifle a giggle as he sniffed the air, the scents of the demonic clogging his nose as he sought out his next target.

Ghostly fingers closed over his sword as he sniffed out one close by, taking off in a silent sprint towards his next target. All these demons, at least one would have the answers he sought. He would find out how to turn a demon back into a human. And there was nothing anyone could do to stop him.

The sun rose on the seventh day, marking the end of his time in the forest. 

Seven long nights, followed by seven longer days. Long enough for him to get used to how it worked. Long enough to realize he couldn't sleep. 

He'd lain for perhaps two hours, tossing and turning with his eyes closed. But it made no difference; he couldn't sleep. He didn't feel tired, but definitely overwhelmed, given that the closest he could get to relaxing was deep meditation, where he could pretend he wasn't conscious. He'd spent that time instead practicing his tangibility. He'd spent long hours simply shifting from tangible to intangible, visible to invisible, flickering between the two to try and master it. It wasn't easy, but with all the time in the world and tons of opponents raring to go, he made do.

It was also easy. He was always full of energy, feeling constantly revitalized, even after hours without a break. Ironically, he was like a ghost as he hunted the woods at night, preying on the demons that lurked all around. Sometimes he sneaked behind them and killed them before they knew what was happening. Other times, he let them strike first, watching their expressions turn from triumph to horror as their attacks phased through. Most times, however, he'd let them look into his cold, unfeeling mask that only allowed his similarly cold eyes to peek through as he interrogated them for answers. They never had anything of value, but he still needed to check. It just wouldn't do if he accidentally killed a demon who knew something.

He'd taken to following people, too. One boy with yellow hair jumped at every sound for four hours straight one night, and he was torn between finding it deeply amusing or deeply concerning. Maybe he sensed Tanjirou's eyes on him and became paranoid when he couldn't locate the source, or maybe he was just like that. Either way, he left him alone soon enough.

One girl was almost as spectral as himself, but the fact that she remained unaware of his presence the entirety of the fifth day as she collected water and foraged for food led him to believe she was still alive. She was interesting, though, and he wondered what that coin meant, considering she flipped it before doing absolutely everything. It was probably a comfort item; he hoped it worked.

A crow flew overhead, diving down when it saw him standing in the morning sun. "The selection is over! The selection is over!" It cawed, flying around his head in a lazy circle. "Head down the mountain now! I repeat, head down the mountain!"

He smiled gratefully at the bird, nodding once before walking down with a pleasant smile on his face.

For all the horrors this mountain contained, in the daylight, it was beautiful. He stepped over a small, bubbling creek as sunlight filtered through the leaves above. He basked in the fresh air and morning light, and despite the fact that he'd literally died here, he had a feeling he would miss the peaceful mornings.

He emerged silently into the clearing, where a few other candidates stood. The girl he'd shadowed was already there, and they locked eyes as she took in his pristine mask before turning away from one another. At least he wasn't the only candidate without a scratch; it made him less suspicious. The yellow boy was here too, though he looked more dead than Tanjirou himself. He was mumbling over and over about how he'd die regardless, and that he might as well be dead already.

There was also a scarred boy in a purple uniform, who was huffing to himself in a corner. He'd seen a couple of spirits wander the mountainside while on his way down, but he assumed most others had either moved on or headed home. Still... this wasn't it, right? Three survivors and a ghost? That couldn't be all that passed the selection. He'd already confirmed that the Hand Demon was he strongest in the forest, so there was no way that many trainees died to basic demons.

"Congratulations on surviving the final selection, and we are glad you made it back safe." The two guides spoke in unison. Or... maybe not. Wow, did their masters even care about them? Who would send someone to demon mountain if they couldn't fight demons?

"So, we made it back alive." The scarred boy grumbled, making Tanjirou's fingers tense imperceptibly. "Big whoop, when do I get my sword?"

"All will come in time." The black haired guide stated simply. "You have all passed final selection and therefore, have been accepted into the Demon Slayer Corps. The Demon Slayer Corps is made out of 10 ranks, ranging from Kinoe to Mizunoto. As recruits, you will begin at the lowest rank of Mizunoto and gain rank through your feats in the Corps. To begin, you will be given a uniform, rank insignia, a sword, and be assigned your own Kasugai Crow."

The guide clapped their hands, and crows descended from the sky towards them. He raised an arm for the bird to perch on, before reaching up to stroke them behind the ears. He cooed softly at his touch, making him smile behind his mask. He pulled it to the side, revealing his face. "Hey there, oh, you're pretty, aren't you? I hope we get along well." He murmured softly, with a small smile. He didn't notice the girl with a butterfly in her hair give him a slight glance from her spot perched with her own crow.

"A Kasugai crow is used for several purposes, but its most important duty to you is communication. From it, you will receive your missions and various correspondence. Now, we-" The white haired guide was cut off when the scarred boy lost his patience. He swore, throwing out his arm to shoo the bird away. "Who gives a crap about this stupid shit!?" He yelled, advancing on the little girl.

Tanjirou frowned, sliding his warding mask back into place as he watched him approach.

He watched as the boy grabbed the guide by the arm, yelling into her face. "I want my sword! You know, the color-changing katana! Give it to me now!" He yelled, cocking back a fist.

Tanjirou decided he's seen enough. He set down his crow and rushed to intercept as he grabbed a firm hold on the boy's arm.

"Let go, now." He said, glaring at the boy through his mask. "If you don't, I'll break your arm."

The boy flinched as he was faced with such a cold, unfeeling gaze through the impersonal wood of the warding mask, but held firm. "I- I'd like to see you try!" He yelled.

Tanjirou gritted his teeth and drew in a breath before applying extreme pressure with his hand. There was an audible crunch as bone fractured in his grip.

"Aw, crap!" The boy yelled, withdrawing his hand to cradle it.

"I did warn you." He said coldly, before turning to the girl. "Are you alright?" He asked softly, cocking his head.

"I'm fine, thank you." She replied in the same monotone as before.

"If you're finished chatting, we can move on." The black haired guide said from the sidelines, turning to move towards a table at the back of the spot. The white haired guide followed them, and they stood side by side once more. "Here you will be able to choose the ore that will be used to forge your sword, choose wisely."

He was at a loss on what to choose, and it seemed everyone else was too. The girl with the butterfly pin just flipped a coin every few seconds, but made no move towards an ore. Tanjirou lightly sniffed the air, and one piece caught his attention. He grasped it; he didn't know how much the ore would affect his sword, but he wanted it to be the best it could possibly be.

And with that, he descended down the mountain, heading back to Urokodaki.

Shinobu's smile became slightly more real when Kanao came back through the door, completely unharmed save for a bit of dirt on her uniform. She never doubted she'd make it back, of course, but it was nice knowing she was safe.

"How was it Kanao? Did you have fun?" She asked. She nodded, her smile still in place, but something seemed tight about it. She must have a question.

Like clockwork, she pulled the coin from her pocket and flipped it, nodding at the result. She turned to face her. "Kochou?" She asked. "Does Tomioka-san have a tsuguko?" She asked.

Shinobu almost did a double-take. She was expecting a myriad of questions, but not that. "Not to my knowledge, why?" She asked.

"There was a water-breath user who acted just like him. He was completely unharmed and undirtied, too." She said simply, before turning to leave.

Now that was interesting. Did Tomioka have a student? It would be just like him not to tell her about them, she sighed to herself. Well, there was only one way to find out. She pulled out paper and began to draft a letter. "He better have a good explanation for this. And here I thought we were friends." She remarked to herself.

Either way, this second Tomioka would be someone to keep an eye on. He'd have to have done a bit more than act like him to catch Kanao's attention.

Tanjirou walked down the mountain path, daylight fading. The warding mask was worn on the side of his head as he casually strode up the mountainside. He'd kept pace the entirety of the way, yet at this rate, he wouldn't make it back before nightfall. Still, he kept walking. He didn't feel tired, but he'd rather not spend too long exposed when he didn't know what was out there. He still had Urokodaki's sword, but he didn't want to use it right now. He just wanted to sit by Nezuko and destress.

Of course, soon he crested the hill and Urokodaki's small house was brought into view. He could see movement out of the corner of his eye, but when he glanced, it was only an excited spirit climbing up a tree. He waved, and they waved back with a grin.

Suddenly, a loud crash sounded, and the door flew off its hinges. Nezuko walked into view. Awake. Alive! 

He rushed to her, she noticed halfway, and ran to meet him. He brought her into a tearful embrace as they sank to the ground together. "Nezuko! Why'd you have to go and sleep so long!" He sobbed into her kimono. "Do you have any idea how worried I was!? I- I thought you weren't gonna wake up!"

She nuzzled into him, and soon Urokodaki joined the embrace. "You came back." He said shakily, and Tanjirou thought he might be crying. "I almost didn't dare to hope, but you came back alive!"

Neither Nezuko or Urokodaki noticed his wince, but some of the other spirits did, with Hinata shooting him a sympathetic glance over Urokodaki's shoulder. He couldn't tell him. It would break him to know the truth. 

So he just hugged him back with all his might and sobbed into the night.

Later that evening, when everyone had gone to sleep, he went out to walk. He didn't bother with the door; he just took one last look at Nezuko's slumbering form, kissed her on the forehead, and walked through the wall.

He didn't even realize where he was going until he stood in the clearing, the split boulder standing before him. He sighed as he traced the stone with his hands. This was supposed to mean he was ready, that he wouldn't die. But he'd failed.

His ears picked up snow crunching behind him, and he turned to meet the lavender eyes of Sabito.

Sabito's eyes widened as they made eye contact, things clicking into place as he realized that he could see him and what it meant. He walked forward and took his hand into his, hearing a soft gasp from Makomo a little ways away.

"Hey guys... I'm back." He mumbled, tracing over Sabito's hands with his own. Sabito looked at him with horrified eyes until a small form impacted him, wrapping him in a hug. Something wet pressed against him, and he realized Makomo was crying. He held her tight, extending an arm to Sabito who carefully joined the hug. Tears welled in his eyes as he hugged them both.

"I'm so sorry."

Chapter Text

"I failed. I- I'm so sorry! I - I just-"

His breath hitched as it all came pouring out. Every emotion he'd hidden under the surface and beneath his mask came bursting out in one big flow. He'd been pretending everything was fine, that he was safe, that he was alive all day. Every day. For a week. He'd looked Urokodaki in the eyes and lied to his face, telling him he'd made it out. He didn't tell him his student was a failure, how could he? Not when he was looking into those eyes filled with pride and sorrow, looking at him as if he might be a ghost already. Urokodaki had no idea he was right. He couldn't know he was right. But still, he needed to apologize to someone for failing; it might as well be the two people he failed the most.

Sabito flinched when he apologized, and he felt Makomo grip him even tighter as tears of her own poured down her face. He'd never really seen her express that much; she was always composed and in control. Now she was completely distraught, looking at him through teary eyes as she clutched desperately at his haori, her shoulders shuddering as if a dam had breached within her and she couldn't possibly even dream of holding it back.

Sabito was crying too, but more free flowing, like he himself didn't know he was crying. Sabito held him gently, looking into his eyes as if he could find out the answers he was searching for just by looking into them. His face looked so lost, like he couldn't possibly fathom that Tanjirou had died. His evident faith in him only made his failings hurt worse.

"I- I couldn't- couldn't do it!" He cried, clinging to them desperately. "I- I got so close, b- but it w- wasn't enough! I wasn't enough..." He buried his head into Sabito's shoulder and returned Makomo's tight squeeze with one arm. "I'm so so sorry!"

"Don't apologize!" Makomo sobbed, grief evident in her voice. "You did everything you could, I'm sure of it!"

Everything he could should have been enough. They'd spent a whole year perfecting his every technique, hammering it into the marrow of his bones. He'd been pushed until he couldn't stand and then pushed some more. He should have been ready, he should have done it, yet he'd failed. He couldn't even do this right.

"B- but the others," Sabito mumbled. "They came back. They said it was dead. They said you did it." He said in shock, like he couldn't believe Tanjirou was in his arms, apologizing for failing him right now. "H- how are you..."

"I died, but somehow I can..." He trailed off, sniffling. "I was still able to kill it as a ghost."

He heard Makomo's sobs hitch, and Sabito still. "W- What?" He asked, pulling Tanjirou's head from his shoulder to cup his cheek gently and look into his eyes. Makomo pulled off him slightly, wiping her eyes with her sleeve as she looked at him in bewilderment and shock.

He gave them both one last squeeze before walking over to a tree on the side of the clearing. He focused on his breathing, channeling all his power into his fist, and punched forward, leaving behind a crater the size of his fist in the wood. It hurt, but the pain was only temporary. He had a splinter, but he just dropped his corporeal state, and it dropped right through. He turned back to the pair of ghosts, waving his hands in a 'Ta-da!" motion that lacked any real flair.

Sabito walked forward, ghostly fingers passing over the splinters of wood. "This is real damage," He murmured, turning to Tanjirou with wide eyes. Makomo wasn't far behind, taking his hand and examining it in wonder.

"Urokodaki doesn't know I died." He said quietly, watching them stiffen in realization. "People can see me, like I never died at all. I couldn't tell him, I think it'd break him to know the truth, that I failed."

"Stop saying that!" Sabito yelled suddenly, glaring with a fire in his eyes that made Tanjirou shrink back. "Stop saying you failed! You didn't! You won, you beat that fucking demon, and even if you hadn't, you still wouldn't have failed us! You could never fail us!" 

"I don't doubt you did everything in your power to come out on top, Tanjirou-kun. And in the end, you did, didn't you?" Makomo said, running her hands over his, before pulling him into another hug. "And I doubt you're letting death stop you when you can still fight." She then turned to look him in the eyes, giving him a small smile. "No matter what you think happened out there, you made us proud. Okay?"

For what felt like the fourth time that day, he felt tears well in his eyes as he pulled Makomo tighter, before feeling Sabito awkwardly wrap his hands around both of them. "Heh, I really need to stop crying so much." He giggled. It felt good, being around people who knew. But somehow, their saying they were proud, that he didn't waste the year they spent training him, made him feel so much better, even if he didn't believe it himself.

Makomo hugged Tanjirou back hard. It was something she'd wanted to do for a while, back when they were still training him for the final selection, but couldn't. It felt nice to finally be able to hold him close, even if the circumstances were horrifying to think about. She still felt ill; the shock that Tanjirou hadn't made it after all nearly made her throw up. It was a good thing she physically couldn't anymore. "I think it's okay to cry, especially now. It means you're still you." She could tell Tanjirou didn't believe them about not having failed, but that was okay. She could believe it for him, until he time came when he was ready to believe it himself. 

"So, you'll be heading out soon. As a member of the Corp," Sabito said, pulling away to eye Tanjirou's new mask, smiling at the craftsmanship. It definitely suited him, through and through. A shining sun.

Tanjirou nodded at him, playing with Makomo's hair absentmindedly. That was also something Makomo always wanted to do. Sue her, Tanjirou was nice and sweet, and even brought her gifts. She couldn't actually do anything with them, but she always appreciated the sentiment. 

"Then I'll come with you." He said, nodding to himself, taking Tanjirou by surprise. "You'll need the company, and your sister can't exactly talk."

"I'll come too. You'll need someone to guide you to improve. It'll be just like before." Makomo smiled, reminiscing about the year they'd spent together, all the talks they'd had about unrelated things. She'd never known family outside Urokodaki, no siblings or cousins, but she'd liked to believe it would have been something like that. 

Tanjirou let his smile become a bit wider before stretching out his arm to pull Sabito back into a bone-crushing hug. "Thanks, guys. You don't know how much that means to me."

Tanjirou then fell into a routine over the coming days. He didn't really have a lot to do until his sword came, so he spent most mornings with Urokodaki and Nezuko. He'd help out around the house, play with Nezuko, tell her about everything that'd happened minus his death, cook meals, and pretend he couldn't see Makomo and Sabito poking around the house. On afternoons, however, he threw himself into training.

He couldn't exactly build up muscle anymore, but he hoped he could at least build up power. He ran laps even though he couldn't really tire, and swung his sword thousands of times, with each repetition meticulously inspected to improve the fluidity and perfection of each strike.

He ventured to the boulder clearing every day to spar with Sabito once more. What were once one-sided beatdowns had now become fierce battles that Makomo watched with full focus. Sabito actually had to push himself to keep up with Tanjirou, the force of the blows shaking their wooden practice swords down to their splinters.

Makomo was a different fighter altogether, and he quickly understood why the Hand Demon remembered her as the agile one. That girl was fast.

She darted around the clearing, dashing in quick strikes that left him pivoting on his feet to block the onslaught of blows. She came from all directions, she leapt high, ducked low, one time she even managed to run up a tree, launching into the air and jump slashed him in an overhead gambit purely for style points. It wasn't useful and was very easy to dodge, but she definitely looked cool while doing it, which was what he thought she was going for.

All in all, he could even say he was having fun.

That morning, Tanjirou pulled his haori over his shoulders before pulling on his shoes. "Alright! I'm gonna go out to train, Urokodaki! I'll be back in a bit!" He called off into the house.

Urokodaki just chuckled. "Alright, but don't go pushing yourself too hard, ya'hear? You're meant to take it easy till ya get a mission!"

Sabito, who was standing right next to him, just laughed. "Boy, you're sure in a hurry to get your ass kicked. What, haven't had enough?" 

Tanjirou just glared at him, since answering verbally would make him look crazy. "Don't worry, I'll be careful!" He said with a grin, before affixing his mask to his face and walking out into the cold winter's air. Sabito followed close behind, whistling to himself.

Tanjirou walked over to the line of bokken that lay off to the side of the house and picked one to take to the clearing. He tested the weight in one hand before sliding it into an empty sheath and attaching it to the hip.

"Try not to break it this time, okay?" Sabito remarked, giving him a sly side-eye. "Urokodaki is bound to notice his bokken going missing if you repeat what happened yesterday." 

"Oh hush!" He whispered loudly, turning to him. Yesterday, the bokken he'd borrowed had been smashed to splinters when Tanjirou tried to force his way through Sabito's guard. He'd have to replace it sooner or later, because he didn't doubt that Urokodaki kept count. 

"And if he notices," Sabito continued, walking closer to flick him on the nose. "He'll... what was it? Oh yeah, 'Break every bone in your body.'" 

"You were there for that?" Tanjirou questioned. "I didn't even see you!"

"No, I wasn't." Sabito smirked. "He just told me the exact same thing. Though actually, maybe you should tell him. I wanna see if your bones can even break."

Tanjirou giggled and shoved him into the line of bokken, making a thud against the wall and the line of wooden swords to tumble down. There was a pause as the grins slipped from both their faces, as Sabito reached down and wrapped a hand around a bokken.

"Umm. What the-" Sabito started, before a noise spooked them both.

"Tanjirou, I heard a thud. Are you okay!?"

Urokodaki rounded the corner as the bokken suddenly fell through Sabito's fingers. Urokodaki stiffened almost imperceptibly for a fraction of a second before shaking his head. Tanjirou and Sabito exchanged a short glace before Sabito started to creep away. When Urokodaki didn't react, he broke into a sprint and rushed through the treeline.

"I'm fine Urokodaki!" Tanjirou smiled behind the fox mask, trying to portray a sense of normalcy. "I just slipped on the snow and knocked into the bokken. Sorry for worrying you." He bowed, and Urokodaki patted his head fondly.

Unknown to him, behind the mask, Urokodaki was a whirl of emotion. 'Just then, when I rounded the corner, I could have sworn I saw...' 

But no. That was impossible. He was sure he'd seen the peach hair of his former pupil, but then he blinked, and he was gone. This was the first time he'd seen Tanjirou properly wearing the mask he'd given him; until that point, he'd only worn it on the side of his head. His mind probably just got confused for a moment. Sabito was gone; he knew that for sure. But Tanjirou, even if he could sense some difference in him, in his demeanor, and the way he smelled at times, was still here. He shouldn't let such a young mind be wearied with ghosts of the past.

Tanjirou bowed once more before wandering into the forest, leaving his master behind. Today, he headed straight for the clearing. It didn't take long to arrive at the boulder, where Sabito already stood.

Makomo was in a tree overhead, swinging her legs as she looked down on them. She was looking with a questioning gaze at the frozen form of Sabito, who stood there unmoving as a thousand thoughts flared behind his eyes.

"Did that... happen?" Sabito asked, turning to look at him with vulnerable eyes. "I thought... it was only you."

"What?" Makomo asked, leaping down from her tree to stand beside him. "What are you talking about? What happened?" But she got no response. She turned to Tanjirou and repeated her question. "Tanjirou, what happened?"

Tanjirou looked down at the bokken in his grasp, real and solid. He dropped his corporeal form and watched it fall through his fingers, landing softly amongst the snow. He picked it up once more and walked over to a frozen Sabito and irritated Makomo. He grasped Sabito by the hand and felt something within him push. He pressed the bokken into his grip, and it remained there. Even Makomo simply stared at it. Seconds ticked by until suddenly it fell through his grasp once more.

"I think..." Tanjirou began before trailing off. "I think you two may be able to help more than I initially thought."

Chapter Text

The testing that followed their new discovery was extensive. Whilst Sabito was content knowing he could finally slay demons like he trained to do, Makomo and Tanjirou were both very confused on the how’s and were determined to figure both it and the full extensive capabilities of this newfound ability. How did it work? What was the longest they could stay corporeal? What was the trigger? And most importantly, how could they use this in a fight?

Tanjirou had rushed to the house to sneakily grab his notebook to document their findings, tiptoeing past Nezuko’s sleeping form and trying not to alert Urokodaki who was chopping wood out back.

He knew he’d have to be extra careful with the notebook from now on unless he was incredibly vague about what he wrote down. He didn’t know if Nezuko was actually reading it, but just in case she was he wanted her to live thinking her older brother was still with her for as long as he could.

“Okay so…” Tanjirou trailed off, scribbling away. “Test 1, Trigger. Sabito, stay still, I’m going to get slowly closer and I want you to tell me when you feel solid. Okay?”

Sabito nodded, and he took a deep breath. He started 10 paces away and reached for the corporeal thread. He tried to push it to Sabito like he did earlier, but nothing happened. It didn’t connect. Sabito didn’t say anything either so he took another step and repeated. Then another. Then another. It was only when Tanjirou took Sabito’s hand in his own did he feel something give, and Sabito gave a surprised gasp when the feeling of solid flooded him again.

”Skin contact required.” Makomo murmured from the sidelines, prompting Tanjirou to rush to his notebook and scribble the results for future reference. Sabito flexed his hands for a few moments, feeling the cool air wrap around them before it began to fade.

”Alrighty, the next test should be how long we can hold it.” Makomo suggested to Tanjirou. The ghost nodded, scribbling the next test before walking up to a now incorporeal Sabito. “Do your thing, but push as much as you can, okay?”

Tanjirou smiled at her, before interlocking his fingers with Sabito. “Ready?” He asked, looking into his violet eyes. At the boys nod he gripped that string of corporealness and shoved it into him, pushing and pushing until the strand was straining. He almost felt ready to snap as he pulled away, migraine building. He slipped and nearly fell over before Sabito grabbed him to support his weight, looking at him worriedly.

”You okay Tanjirou? Maybe we shouldn’t do that again.” Sabito asked worriedly, pulling the boy closer and weaving an arm under his shoulder to keep him upright. They shuffled to leave Tanjirou slumped against a tree, watching him worriedly even as he tried to reassure them he was fine.

"Guess it just uses more energy than I thought..." Tanjirou tried to chuckle, though he failed to break the sombre mood. He did end up feeling better after a few minutes of rest, and Sabito's corporealness lasted a full 18 hours before he finally faded again. They of course used the time to spar because according to Sabito, holding a real Bokken felt a lot better than the weird spectral Bokken he could for some reason bring out. Tanjirou could agree on some level, it definitely felt more real.

The tests continued after that point, though Makomo made sure Tanjioru didn't overdo his... ghost powers? They still didn't know what energy was being used when they shared corporealness or when they became visible, but whatever it was most likely had some kind of limit that Makomo didn't want them to ever hit even in the name of science.

They found that any kind of contact allowed Tanjirou to give them corporealness, not just hand to hand. They also found that Tanjirou could pull away the corporealness to make them intangible again. They also found that with a specific amount of energy transferred, they could become solid without becoming visible or vice versa. Something Sabito was also pretty excited about.

"That's even better! Because now we can still help even if there are other Demon Slayer around!" He grinned behind his mask, pumping his fist. "We can combine attacks so they have no idea what hits them, together we'll be unstoppable!" 

"True, but there's one problem." Makomo stated. "How do we explain how he fights like two different people are beside him? If a demons head just flies off with his sword barely moving that's going to cause questions. Especially because those types of techniques aren't Water Breathing ones. Even I'm not that fast." That caused them to think. It never really occurred to Tanjirou that he may work beside other Slayers, but it made sense. There would be missions he wouldn't be able to take alone, and he'd be forced to work with someone. So how would they work around it? And what about Nezuko? She would be on their missions together too, so how would he explain to her how he was doing all the ghost stuff?

"We could pretend it's a breathing style." Sabito suggested after a while. "Say he developed techniques rooted in Water Breathing that allow him to dodge whilst looking like he hardly moved a muscle, or disappear without a trace."

"But what if they ask me to teach them? Or for me to demonstrate it?" Tanjirou asked, worriedly. This time Makomo spoke up,

"I can help you with the specifics of the technique, but you could pretend it's personalised. I remember hearing from Urokodaki about a Hashira two centuries ago who used Ice Breathing, but only they could use it because of the specifics of their body. We could play that you have enhanced senses and reflexes that suit you to the style that no one can replicate." She posed. "We could call it Spirit Breathing or Ghost Breathing, a style focussed in stealth, speed, and overwhelming the enemy with sudden ambushes and unpredictable movement."

Tanjirou thought about it quietly, before sighing. "I would be so lost without you guys. Thanks." He said, relieved. 

"No problem, though you should probably start practicing not responding to what we say for when you're on a mission. Your sword arrives in two weeks, right? We'll need to have this fully down by then!" Makomo cheered with her typical bubbly energy returning full force.

Tanjirou didn't respond, just standing up and drawing his sword, which made Sabito and Makomo smirk at each other. He took a stance and took in a deep breath, focussing on he blade in front of him. He didn't really know how to make a breathing style, or how to even develop it properly. Water Breathing was called that because the fighter flowed like a river, their every movement powerful and adaptable. You became so much like a surging tide that water gathered along your blade, the element lending it's strength to your attacks. How was he supposed to improve on that?

Sabito grabbed his hands to steady them, coming up behind him. "Well, the first form is usually the foundation for the others, so let's focus on that for now. It's also almost always a horizontal slash with a bit of movement mixed in depending on the style." He coached. "Remember, it's also something that should be believable that someone could perform it thrice in swift succession if we're going to make our assistance unnoticed."

Tanjirou nodded, before sucking in a breath and slashing forward.

If he was being honest, Urokodaki was curious and concerned. He knew Tanjirou was a very driven boy, but he still didn't expect this level of dedication from him. Something had happened during final selection, something that had convinced him he needed to work harder than he had before. He'd worked tirelessly, even somehow managing to break one of his Bokken during his self imposed training.

Urokodaki had been hoping he might take it slightly easier now he'd become a fully fledged slayer and his sister had woken, but if anything it had just fuelled his drive to work himself harder. What's more, he had no idea what kind of training the boy was doing to break a Bokken by himself, but it must be vigorous if even his equipment faced the brunt of it. So one day, he decided to go out after lunch to check on him. He didn't like invading his privacy, as the boy was free to do as he wished. He didn't even know if they boy was training, for all he knew he was simply playing around in the snow, but he just didn't want him to hurt himself.

It was harder than he thought it would be to find him, his scent was somehow dulled and had been ever since he'd returned. He eventually found him in a place that in hindsight seemed slightly fitting, the clearing where the boulder he was tasked to cut had sat. It now laid in two halves, a reminder of how far the boy had come. He was practicing his breathing techniques, Bokken in hand, but something was wrong. His stance was adjusted, and the way he breathed was different somehow. He could see pieces of the things he'd taught him, but it wasn't Water Breathing, it was all wrong. Then he lunged forward in a flash, form flickering as pale blue flames seemed to creep across the blade. His balance was off though, and he fell short. The ghostly flames dying as quickly as they had sprung to life.

He smiled under his Tengu mask. So that was the reason. Tanjirou was making his own breathing style. 

The more he thought about it, the more sense it made. Tanjirou must have realized he wasn't suited to Water Breathing during the final selection, and set out to make something more for him while he still had time to train. Why he didn't come to him, he didn't know, but clearly he was making good progress on his own. It made sense now, how much time he spent training out here, constructing a technique unique to yourself was no easy feat, yet even having one form was a sign of astounding potential.

He silently crept away from the scene to avoid startling him. He'd let him work on it himself for now, but he was excited for the finished product.

There was something special about Tanjirou, he knew that much. He'd definitely go far. And he couldn't wait to see how far he'd go.

Tanjirou was smiling with Urokodaki, sharing a laugh at something the man had said to keep up appearances when Sabito phased through the wall. Tanjirou didn't let his focus slip, maintaining eye contact with Urokodaki, but he tapped his finger in Sabito's direction to acknowledge that he knew he was there.

"Someone's coming towards the house, I think it's your swordsmith." Sabito told him, casually walking to wave a hand in front of Urokodaki's face as was tradition at that point. Sure enough, an unfamiliar scent caught his attention soon after and he could tell Urokodaki caught it as well. The man simply gestured for him to answer the door, so he probably knew this man as well.

He walked to the front door, seeing Makomo sat on a tree branch outside watching the approaching figure curiously. Sabito walked beside him as the approaching figure drew nearer. He wore a large hat adorned with several windchimes that rang a gentle melody as he stepped. Underneath the brim of the hat, he could barely catch sight of the pale colour of the mans mask.

"Hello there." Tanjirou greeted when the man stopped short before the house, tilting his head slightly.

"My name is Haganezuka." The man stated, speaking slowly to him with an air of grandeur. "I have forged Tanjirou Kamado's sword, I am here to deliver it." 

Unseen to the man, Makomo dropped from the tree behind him. Walking up behind to try and peek at the sword in a way that made Tanjirou have to fight not to crack a smile.

"Oh, uhh." Tanjirou did a hasty bow when he realised he was quiet for too long. "Sorry, I'm Tanjirou Kamado. Please, come inside, I'll make you some tea." He offered, stepping aside to allow Haganezuka to pass.

"This is a Nichirin Sword." Haganezuka continued, seemingly without having heard him. He pulled the cloth wrapped package from his back and crouched, holding it over his knees. "And I forged it." He reiterated, unfolding the cloth from the packaging.

"You must be tired, please, I can get you some-"

"The materials for this kind of sword can only be obtained from the mountain closest to the sun. Forged from Scarlet Iron Sand and Scarlet Ore, they produce the unique product of a steel capable of absorbing sunlight." The man continued on, cutting off his attempts of hospitality which quickly got on his nerves.

"What's with this guy?" Sabito asked pointedly. "He's just ignoring him, is he having some kind of stroke?"

"I think he may just be like that." Makomo said thoughtfully. "I mean, look at his mask and tell me he's completely sane."

"Wow really? That's so interesting." Tanjirou continued, ignoring the ghostly debate around him. "Could you tell me more over some-"

"You see Mt. Yoko is bathed in sunlight all day long, never a single cloud in the sky." He cut him off again, pointing at the sun.

Inside the house, Urokodaki sighed to himself. "He still hasn't changed. The man refuses to listen to a single thing anyone else ever says."

Suddenly, Haganezuka snapped his head up to face him, looking into his eyes with a glaring intensity as he came face to face with a Hyottoko mask. It surprised him so much he nearly lost grip on the corporeal thread, but he caught himself just in time. 

Sabito laughed. "I see what you mean, Makomo! This guy looks unhinged!"

Tanjirou just tried not to feel too unsettled by the intensive eye contact as Haganezuka got close to examine his face. Did he know he was dead? Why was he looking at him like that?

He found himself desperately wishing to pull his Kitsune mask over his face to conceal himself from the mans penateating gaze, but he didn’t want to seem rude.

"Hey... you're a child of brightness, aren't you?" Haganezuka said after a moment of contemplation. "Well, isn't that lucky."

Tanjirou tilted his head. "No, I'm a child of Kie and Tanjuro Kamado." He said, confused.

"Not like that, I mean your hair and eyes. They're red." He said, pushing a finger against his cheek. "When a family that works with fire has a child like you, it's considered lucky and cause for celebration."

Lucky. If Tanjirou were lucky he'd have made it out of final selection alive. If he were lucky, his family would still be alive. If he were lucky, Nezuko wouldn't be a demon. If he were lucky, Sabito and Makomo would have lived and they could have been living out their lives as well.

Tanjirou wasn't so sure he believed in luck anymore.

On the outside, however, he just smile. "Really? I didn't know that! My family were charcoal merchants, so you'd think I would!"

"Indeed, and it's because of this that there's a good chance this sword will turn red! Isn't that right, Urokodaki?"

Tanjirou heard a lengthy sigh from inside the house, followed by a very tired "...yes."

"Well come on! Let's go draw it!" The man said excitedly, before pulling him into the house.

Tanjirou was sat on his knees, the katana laid across his lap in it's sheath. Urokodaki and Haganezuka were sat across from him, and Sabito and Makomo were watching him with clear interest.

“Come on! Draw it already!” Haganezuka encouraged, waving his arms in front of him. “These Nichirin swords are also called ‘Colour Changing Katanas’, because they change colour based on the wielder. So come on! Let’s see it!”

”As much as I hate to support the nutjob, I’m curious too.” Sabito called from the sidelines, smirk evident behind his mask.

Not wanting to waste any time, Tanjirou drew the blade from its sheath. He gripped its hilt with both hands, bringing it up to the light to admire its craftsmanship. Crazy or not, Haganezuka was a damn good smith.

Then, starting at the base and working its way up, its colour began to shift. A brilliant, ghostly white consuming the grey of the steel until it was all that was left.

”White!?” Haganezuka exclaimed from the sidelines, confusion and exasperation in his tone.

”That’s… incredibly odd.” Urokodaki spoke, a touch of apprehension in his voice as he looked at the blade.

”Why, is it bad?” Tanjirou asked, flicking the blade so it caught the light with fascination.

“I don’t think so, no. It’s just…” Urokodaki struggled for words, so Haganezuka just decided to rip the bandage off.

”Nichirin blades only ever turn white like that when their bearer dies.” He stated, in a fascinated tone. “I was hoping for red, but this… this is a discovery!” He yelled excitedly.

All three ghosts in the room froze. The blade knew he was dead. How? It must be something to do with his lack of corporeal form, right? What did it mean?

”Interesting…” was all Tanjirou could say, mind whirring.

”Maybe it has something to do with that breathing style you’ve been working on.” Urokodaki posed, which made Tanjirou’s cheeks flush. So he knew.

He was about to apologise but Urokodaki raised a hand to stop him. “No need. To be honest, I could tell you weren’t perfectly suited for Water Breathing. Making your own form is admirable, and if this tells us anything, it’s that there wasn’t going to be a form you could have learned suited for you. I’m proud.” He said encouragingly.

Suddenly, a crow fluttered down through the window, before screeching a message. He had his first mission.

Tanjirou took a deep breath.

Time for the next step.