Chapter Text
The world had always been grey.
Muichiro didn't remember the last time he had seen colour. Maybe he had once, maybe there had been a time when the sky was blue, when the wisteria trees surrounding the Demon Slayer headquarters were more than varying shades of washed out grey. Maybe his uniform had been black, not just another dull tone that blended into the rest of the world.
But he didn't know.
And it wasn't like anyone would explain it to him.
The other Hashira didn't talk to him much unless they needed something. Sparring, mostly. He was fast and precise, good for testing their endurance, their speed. They didn't seem to mind that he barely spoke in return, that he forgot things often, that his mind sometimes wandered in the middle of a fight and left him standing motionless, staring into the fog that filled his brain.
Maybe that was why they didn't bother with him much. Muichiro knew he was different. His thoughts slipped through his fingers like water, difficult to hold onto. He didn't always know what people meant when they spoke to him. He barely remembered his own past, let alone the small details that made up day to day life. And emotions, he didn't understand those at all.
Still, he did what he was told. That was enough.
Or at least, it had been until today.
Muichiro was in the training pavilion, practicing his stance. His sword felt heavier than usual, like something was off in his grip. His body moved out of habit, but his arms and legs weren't positioned quite right. He could feel it, but he didn't know how to fix it.
Then, someone spoke.
"You're too stiff."
Muichiro blinked. He hadn't noticed anyone nearby, but when he turned, he found Giyuu Tomioka standing a short distance away, watching him. His face was blank, as it usually was, but Muichiro had noticed that Giyuu didn't talk much either.
"Am I?" Muichiro asked, tilting his head slightly.
Giyuu stepped closer. His movements were slow, careful, like he knew Muichiro might flinch away at sudden contact. "You're gripping your katana too tightly. Loosen your fingers."
Muichiro looked down at his hands, then back at Giyuu. "Why?"
"So you don't waste energy." Giyuu stepped behind him, close but not touching. "May I?"
Muichiro hesitated. People didn't usually ask before correcting him. They just did it. He didn't know why Giyuu was bothering with politeness, but after a brief pause, he nodded.
Giyuu reached out, adjusting Muichiro's grip with steady hands. His fingers were warm against Muichiro's skin.
"There," Giyuu murmured, stepping back. "Try again."
Muichiro raised his sword, and this time, it felt... better. Lighter. His wrist moved more fluidly, his stance more balanced. He glanced over his shoulder at Giyuu. "You were right."
"I know."
Muichiro blinked at him. "How?”
Giyuu's lips twitched. "Just did."
Muichiro didn't know what to say to that, so he said nothing at all.
He was used to silence. It was easier than trying to make sense of conversations he didn't understand. But with Giyuu, the silence didn't feel uncomfortable. It was just there, existing.
And for some reason, standing in that grey
washed pavilion, with Giyuu's careful gaze watching over him…
Muichiro felt safe.
The first time it happened, Muichiro thought he was imagining it.
It was faint, barely there, a trick of the light, surely. But as he trained, something flickered at the edges of his vision, something different from the usual shades of grey.
The tips of his fingers, the fabric of his sleeve, there was something... warmer about them. Not grey. Not quite.
A dullness, but not the usual kind.
And when he looked at Giyuu, standing off to the side, arms crossed as he observed, he saw it again, this time in his haori.
The usual blacks and greys seemed softer, edged with something he didn't have a name for.
Muichiro frowned.
Later, when he sat alone beneath the pavilion's roof, he thought about colours. He had read about them before, blue, red, yellow, green. But the words didn't mean much to him. He knew they were important, but he didn't remember what they looked like.
Would he ever?
He didn't know.
But as the days passed, the flickers became harder to ignore.
The grass under his feet felt less like a smudge of grey and more like something new, something faint and strange, something almost green. He couldn't be sure, but when he trained alongside Giyuu, he sometimes caught glimpses of it in the sky, too. A washed out kind of blue, perhaps.
Still, it wasn't until one particular evening that the change truly sank in.
Muichiro had been walking along the path leading away from the pavilion when he stopped, something catching his eye.
A butterfly.
It was fluttering just a few feet away, its wings delicate, moving lazily through the air. But Muichiro didn't care about the butterfly itself.
He cared about its colour.
Bright. Vibrant.
Something that had never been there before.
Not grey. Not black. Not white.
He didn't know what colour it was. He had no name for it. But it was real.
He reached out, just barely brushing his fingers against the air where the butterfly had been before it flitted away.
A deep breath.
And then, he turned, only to find Giyuu standing behind him, watching.
"...You saw it, didn't you?" Giyuu asked. His voice was quiet, careful.
Muichiro didn't answer at first. He looked down at his own hands, flexing his fingers. "I think so."
Giyuu hesitated. Then: "What did it look like?"
Muichiro shook his head. "I don't know."
Giyuu studied him for a long moment, then softly, barely above a whisper, he said, "It was orange."
Orange.
Muichiro rolled the word around in his mind. He liked it.
He glanced back up at Giyuu. "How do you know?"
Giyuu looked at him like he wanted to say something, like there was more to his words than he was letting on. But in the end, all he said was, "Because I can see colours."
Muichiro tilted his head. "What does that feel like?"
Giyuu's lips twitched, just barely. "Normal."
Muichiro thought about that. About the butterfly. About the way his world was changing, slowly, piece by piece.
And for the first time in a long while, he thought, maybe one day, normal wouldn't seem so far away.
Weeks passed, and the colours didn't disappear.
They came slowly, in fragments, in small, fleeting moments that left Muichiro both confused and fascinated.
The first time he saw the sky properly, he stood outside for hours, staring at it. Blue. That's what blue looks like. He still didn't understand why, but he liked it. It wasn't as harsh as he thought it would be, not as overwhelming as he'd feared. It was soft. Gentle. Like a whisper against his skin.
Then there was the grass. Green. A different kind of warmth, one that made the ground feel more alive beneath his feet.
And then Giyuu.
The first time Muichiro saw his haori in full colour, he had to stop himself from staring.
One side was multicolored. The other side was different. A deep, rich colour, one he couldn't describe, but he knew it wasn't grey.
"What colour is that?" Muichiro had asked one day, when Giyuu had joined him in the pavilion again.
Giyuu followed his gaze down to his own sleeve, brushing his fingers over the fabric.
"Burgundy."
Muichiro let the word settle in his mind. He liked that one, too.
Muichiro wasn't sure if the other Hashira had noticed the difference in him. If they had, they didn't say anything. He was still the same to them, still the quiet one, the one they used to spar with, the one who never fully seemed to belong.
That was fine. He didn't care.
But he found himself seeking out Giyuu more often.
Not on purpose. Not at first.
It just happened that way.
One evening, he was sitting outside, watching the sunset. He wasn't sure why. The colours weren't all there yet, only hints of warmth on the horizon, edges of gold and red bleeding into the blue and grey. But it was... nice.
He barely noticed when Giyuu sat down beside him.
They sat in silence for a while. That was normal. Neither of them minded.
Then Giyuu spoke.
"You've been seeing colours more often."
Muichiro nodded. "Mm."
Another pause. Then, “Why do you think that is?"
Muichiro thought about that. He thought about the weeks that had passed, about the subtle shifts in his vision, about the quiet, careful moments he'd spent with Giyuu.
"I don't know." He glanced at Giyuu, studying his face. "But... I think it's because of you."
Giyuu's expression didn't change much, but something in his eyes softened. "Because of me?"
Muichiro turned back to the horizon. "I think so."
He didn't understand why. But he had a feeling that maybe, just maybe, the fog in his mind, the one that had swallowed his memories, his emotions, his world, was starting to lift.
And for the first time, he didn't feel like he was drowning in it.
For the first time, he thought, maybe he wasn't as alone as he had once believed.
Muichiro wasn't sure when it happened. When Giyuu became something more than just another Hashira he occasionally trained with.
It wasn't a sudden realisation, nor was it anything he'd deliberately thought about. It was just something that... settled into place. Like a puzzle piece clicking into its rightful spot, like the sky stretching endlessly above him, unchanging yet always present.
Giyuu was constant. Steady. Someone he could be around without feeling the need to fill the silence with meaningless words. Someone who didn't expect him to be anything other than what he was.
And maybe that was why, when Muichiro saw colour, it was always more vivid in Giyuu's presence.
He didn't understand why.
Didn't know how.
But the answer didn't seem as important as the simple fact that it happened.
Because whenever he sat beside Giyuu, whenever they trained together or shared quiet company, the dull greys of the world shifted, subtle at first, faint like an afterimage, but growing richer, more defined. The warmth of the sky at dusk. The cool green of the trees. The deep, solemn shade of Giyuu's haori.
And sometimes, sometimes, when the light caught just right, Muichiro swore he could see the dark navy blue of Giyuu's eyes.
• • •
The day was cold. The air carried the crisp bite of the season, seeping through the walls of Giyuu's estate. Muichiro sat cross legged on the tatami floor, a cup of tea resting between his hands, letting the warmth sink into his skin.
Giyuu sat across from him, his posture stiff but not uncomfortable. His fingers idly traced the rim of his own cup, though he didn't take a sip. His eyes were cast downward, unfocused, lost in some distant thought.
Muichiro wasn't sure what weighed on his mind today, but he didn't ask.
He didn't need to.
Instead, he simply watched as Giyuu reached for a spare sheet of parchment lying nearby and began folding.
Slow, precise movements. Crisp edges, careful creases.
Muichiro tilted his head. "What are you doing?"
Giyuu didn't look up. "Folding a paper plane."
A flicker of memory stirred in Muichiro's mind. Paper. Folding. Flying. He knew this. He had done this before.
His fingers twitched against his cup.
"Can I join?"
Giyuu glanced up at him then, something quiet passed through his expression before his lips curved, just the smallest bit, but Muichiro caught it.
"Sure."
Muichiro set his tea aside and took a sheet of paper for himself. His hands worked instinctively, following a muscle memory buried somewhere beneath the fog of his mind. His fingers pressed folds into place, shaping the paper into something light, something meant to soar.
By the time they were done, a small fleet of planes sat between them. Some folded perfectly, others slightly uneven, but none of that mattered.
Muichiro was already standing.
"Let's go outside," he said.
Giyuu hesitated for only a moment before nodding, gathering the planes in his hands and following him out.
The cold air bit at Muichiro's cheeks as they stepped onto the engawa, but he barely noticed. He was more focused on the open space before them, on the way the wind moved through the courtyard.
He picked up one of the planes, holding it between his fingers, testing its weight.
Then, with a sharp flick of his wrist, he sent it flying.
It soared, cutting through the crisp air, gliding in lazy loops before spiraling down.
Muichiro blinked after it, watching its descent, a strange warmth spreading through his chest.
Giyuu followed suit, launching one of his own. His was more precise, following a smoother arc before dipping toward the ground.
Muichiro turned to him. "That was a good one."
Giyuu huffed softly, shaking his head. "Yours went farther."
Muichiro considered that, then shrugged. "Maybe."
And then, before he could stop himself, he smiled.
It wasn't much, just a small quirk of his lips, barely there, but it was.
And for the first time, he thought Giyuu saw it.
Because Giyuu didn't say anything. Didn't make a comment or react with surprise.
He simply met Muichiro's gaze, the faintest pink on his cheeks from the cold, dark rings beneath his tired eyes, and smiled back.
Colours in the Cold
Muichiro didn't understand it.
Didn't understand why he could see more colour here, why it always seemed clearer around Giyuu.
But as he stood there, watching the paper planes settle into the frost dusted grass, watching the deep navy of Giyuu's eyes catch the waning light, he thought, maybe, he didn't need to.
Because for the first time in a long, long time, something in his chest felt warm.
The afternoon air was still, wrapping around the estate like a soft blanket. A faint breeze stirred the paper planes where they had fallen, their folded edges catching the dimming light. The cold had settled deep into Muichiro's limbs, making him feel sluggish, his body weighed down by exhaustion.
He hadn't realized how much energy he had spent until they stepped back inside.
Giyuu moved toward the living room, settling onto the tatami floor without a word. He sat with one knee bent, the other leg stretched out, resting an arm on his raised knee. His other hand idly traced along the rim of his sleeve, a quiet fidget.
Muichiro stood for a moment, looking at him, then without thinking, stepped forward and curled up beside him.
He barely hesitated.
His body moved on instinct, drawn to warmth, to something safe. His exhaustion made him unbothered by propriety, by the expectations that came with being a Hashira.
So he simply settled down, resting his head against Giyuu's leg, his small frame fitting easily against the older man's side.
Giyuu stiffened slightly. His entire body tensed, his muscles locking up as if unsure how to respond. Muichiro noticed, but he didn't move away.
Instead, he murmured, "You're warm."
A beat of silence passed.
Then, slowly, Giyuu exhaled, his posture loosening. He didn't push Muichiro away, didn't tell him to sit up or move. Instead, he allowed the quiet to stretch between them, settling into it as naturally as the shift of the seasons.
Muichiro let out a soft breath, gazing up at the ceiling, his mind drifting.
After a moment, a thought surfaced, a question that had been lingering in the depths of his mind for a while.
"Have you always been able to see colour?"
To anyone else, it would have seemed like a strange thing to ask.
But deep down, Muichiro had a gut instinct that Giyuu was more similar to him than he had initially thought.
He felt Giyuu's leg shift slightly beneath him, his fingers stilling against the fabric of his haori.
"...No."
Muichiro blinked.
He turned his head slightly, glancing up, catching the way Giyuu's gaze flickered away, as if hesitant to reveal more.
But then Giyuu sighed, his voice quieter than before.
"After losing my sister... and my best friend... colour vanished from my life. All I saw was black, grey, and white. Urokodaki told me it was due to trauma."
Muichiro let that sink in.
He had also been told that his memory loss and colour blindness were a result of trauma. His mind's way of protecting itself, of blocking out the things that had hurt him.
The beautiful colours he longed to see. The memories that made him who he was.
No matter how painful they were.
But the other thing that surprised Muichiro... was that Giyuu had lost so much too.
His sister. His best friend.
Muichiro's chest ached with something unfamiliar, an echo of an emotion he couldn't quite name.
He stared ahead, letting his thoughts swirl.
A brother.
He had lost a brother.
Hadn't he?
The memory was faint, as if obscured by fog, but the pain was there. Lingering at the edges of his mind, a whisper of something once whole, now shattered.
His voice came out softer this time, hesitant. "What happened to your parents?"
Giyuu didn't answer right away.
Muichiro wondered if he had asked too much, if Giyuu would shut him out the way most others did.
"...Died from a sickness when I was young."
Muichiro's fingers curled slightly against the fabric of his own sleeve.
Strange.
That, too, felt familiar.
Like a distant melody playing in the back of his mind, just out of reach.
He remembered someone dying from sickness.
Someone who had been close to him.
His mother, maybe?
The thought made his chest feel tight. He wished he could remember. He wished he could put the pieces together, make sense of the fragments left behind.
But they remained just beyond his grasp.
He swallowed, shifting slightly, pressing his cheek more firmly against Giyuu's leg.
"...How did you get your colour back?"
He wasn't sure what compelled him to ask. The words had slipped from his lips before he had a chance to stop them.
Giyuu sighed again.
Then, after a long pause, he said, "I learned to overcome my pain. My grief. My loneliness." A faint frown pulled at his mouth. "I pushed it all away. I learned to let people in again."
Muichiro didn't fully understand what that meant.
But he did know that colour had started to return to him, little by little.
And he knew, deep in his chest, in the place where certainty lay dormant, that Giyuu was the reason why.
His presence. His patience.
His warmth.
Muichiro's eyes felt heavy, his exhaustion creeping in deeper, making his limbs feel heavier.
His voice was quieter now, more distant.
"You remind me of my brother."
Giyuu glanced down at him. "Oh?"
Muichiro nodded sleepily, his breathing slowing.
"He had dark hair... and mysterious eyes like yours."
The words felt like a memory slipping through his fingers, but he didn't try to chase them.
Because he knew it was real.
Knew that, somewhere in the life he had lost, there had been a brother with dark hair and eyes that carried a sorrow too heavy for one person to bear.
A silence stretched between them, comfortable, unhurried.
Muichiro yawned, his small frame relaxing further against Giyuu's side.
"His eyes were filled with so much sadness, too."
His voice was barely above a whisper.
And as his exhaustion won out, pulling him deeper into rest, his last thought surfaced, slipping from his lips before he could stop it.
"...It sucks to lose a brother."
A pause.
"But I also gained one."
His eyes fluttered shut.
And for the first time in a long, long time, Muichiro felt safe.
• • •
The passing months transformed Muichiro's world in ways he never could have imagined. Memories, once distant and lost, had slowly begun to return, painting his past with more clarity. The once muted, dull existence he had known was now filled with vibrancy, colours bursting to life with every sunrise, the sky stretching wide in dazzling hues he had never fully appreciated before. The lush green of the meadows, the deep blues of the lake, the fiery glow of the setting sun, and the bright red of freshly ripened berries. He could see it all now, and it was breathtaking.
But beyond the colours, it was the feeling of freedom that had changed Muichiro the most. He was no longer just a warrior, a Hashira bound by duty. He was still that, yes, but he was also just a boy, one who could fold paper planes and send them soaring through the air, who could run barefoot through the grass without a care, who could spend lazy afternoons skimming stones across the lake. He could exist beyond the expectations placed upon him, and that was something he hadn't realized he craved so deeply.
Giyuu had become a steady presence in his life, grounding him in ways Muichiro hadn't thought possible. They had trained together, spent quiet moments sitting beneath the trees, spoken of things that mattered and things that didn't. Muichiro had come to trust him, to rely on him in a way he hadn't with anyone else.
But as the months passed, Muichiro began to notice something shifting in Giyuu.
The older man looked exhausted. The dark circles beneath his eyes had deepened, his already pale skin seeming almost ghostly in the dim light of early mornings. He had grown quieter, more so than usual. Their sparring sessions had dwindled, their long walks had become shorter and less frequent, and when Muichiro visited the Water Estate, he often found Giyuu still in bed long after the sun had risen, or worse, sitting motionless on his futon, dressed but unmoving, as if he couldn't find the strength to start his day.
"It's just the season," Giyuu had told him when Muichiro questioned why they weren't going on walks as often. "The weather's getting colder. It's best not to stray too far."
Muichiro hadn't fully believed him, but he hadn't pushed.
That evening, the two of them sat together in Muichiro's guest room at the Water Estate, the soft golden glow of a candle casting flickering shadows across the walls. Rain pattered steadily against the roof, and the wind howled outside, rattling the wooden shutters. Distant thunder rumbled through the sky, a reminder that winter was settling in.
Muichiro was curled up in his futon, watching the candlelight dance. Giyuu sat on the floor beside him, his posture relaxed but his expression impassive. There was something distant about him tonight, something that made Muichiro uneasy.
"I received a letter from Master today," Muichiro said, breaking the silence. He turned his head to look at Giyuu. "I'm to leave on a mission at dawn."
Giyuu's gaze shifted toward him, his lips pressing into a thin line.
"But I'll be back in a few days," Muichiro added quickly, a small smile forming on his lips. "Then we can spar again."
For a brief moment, Giyuu's lips curled into a soft smile, but his eyes betrayed him.
The wind outside howled louder, and another clap of thunder echoed through the sky. Muichiro pulled his blanket up higher, suddenly feeling smaller in the vastness of the storm.
Then Giyuu spoke.
His voice was soft, steady. A quiet warmth in the midst of the cold night.
"Mui, I've seen how much you've been through, and I want you to know something important. Even in the hardest moments, you're making progress. It might not always feel like it, but the fact that you're still here, still trying, speaks volumes about your strength. Healing takes time, and it's okay to not have it all figured out right now. You don't have to rush it, and you don't have to do it alone."
Muichiro stared at him, something heavy settling in his chest.
"There will always be ups and downs, days where it feels like you're carrying too much, but the beauty of you, is that you don't give up." Giyuu spoke, tucking the blanket around Muichiro.
"If you ever feel like you're standing at the edge, take a step back, take a breath, and remember that you've faced everything that's come your way so far. And you can keep going. Life is unpredictable, but there's so much ahead, even when it's hard to see. Keep finding things that remind you why you're here, even in the smallest ways.
"When you need someone to lean on, I'm always here for you, just like I'll always be in the quiet spaces of your thoughts, offering what little I can, for as long as I can. But know that your strength, your resilience, it's going to carry you far beyond this moment. You've already started to heal. Just don't be afraid to let other people in."
Muichiro wasn't sure why those words made his throat feel tight.
Maybe it was because he had never had someone tell him those things before. Maybe it was because deep down, a part of him had always feared being alone. Maybe it was because Giyuu was saying something that felt important, even if Muichiro didn't fully understand why.
But he took it in. He let the words settle, let them wrap around his mind and sink deep into his bones.
"...Okay," he murmured, his voice barely above a whisper.
Giyuu didn't say anything more after that. They simply sat in silence, listening to the rain.
• • •
The next morning, Muichiro rose before dawn. The world was still dark, the first hints of light just beginning to creep over the horizon. The rain had stopped, leaving the air crisp and cold.
Giyuu was already awake, waiting for him by the entrance of the estate. His multicoloured haori billowed slightly in the morning breeze.
Muichiro adjusted the sheath for his katana and turned to face him.
"I'll be back soon," he promised.
Giyuu nodded. Then, without hesitation, he stepped forward and pulled Muichiro into a firm embrace.
Muichiro blinked in surprise but quickly melted into the warmth, feeling a strange sense of comfort in the gesture.
"Safe travels," Giyuu murmured against his hair.
Muichiro pulled back and smiled.
Then, just as he turned to leave, Giyuu's voice called after him.
"Remember what I said last night," he said, his tone carrying something heavier than usual. "Don't forget it, Mui."
Muichiro paused.
There was something in the way Giyuu said it. Like it was something more than just advice. Like it was something he needed Muichiro to hold onto, something that would matter later.
Muichiro nodded, offering one last smile before stepping off the porch.
And without another word, he left the Water Estate behind.