Chapter Text
Obviously, as a Hashira, Rengoku’s first responsibility is not training Nezuko. No: it is going on mission after mission after mission, often leaving Nezuko, too inexperienced to be of any use, alone for long stretches of time, with a detailed training regime in hand.
Although she more than understands why, Nezuko honestly hates it when he leaves. For a multitude of reasons, some more embarrassing than others (a nagging fear that won’t leave her, a paranoia that whispers about being alone again, about Rengoku never coming back, of another missing body), but also because it leaves Nezuko with Rengoku’s father and little brother, Senjuro.
Senjuro, of course, was not the issue. No, he’s sweet and kind, too good to Nezuko, even during the first few weeks of her training when she’d been overly snappish and rude. He had continued to smile through it all, though, even supplying her with snacks and soft jokes and compliments on how quickly she was improving—unearned as they were—secretly and slyly poking holes in the jug of bitterness that resided beneath Nezuko’s lungs, remaining patient as it slowly drained, and when Nezuko finally got her act together enough to apologize for her rudeness, Senjuro just waved away the much deserved apology.
“You are grieving,” he had said, endlessly understanding, “And you weren’t mean. Not really. Just quiet.”
He’s even a kind liar.
Nezuko doesn’t deserve a lot of things: to be the only survivor, to have a second chance, to be trained by a Hashira. But perhaps most of all, she doesn’t deserve Senjuro’s constant kindness, and the way he so easily offered her another home, shifting to the side at the dinner table, making space for her when his father would not and when Rengoku was away, somehow discovering her favorite meals and cooking them after the worst of her bad nights, which was, admittedly, every night. He’s the same age as her and yet somehow so much stronger, despite his inability to wield a sword. He’s strong in the ways that matter.
Rengoku does a lot to soothe Nezuko’s rough edges. He gives her hope, bolsters her failing spirits, offers protection as easily as breathing. Senjuro, though. Senjuro gives her a home.
(Not, of course, that Nezuko realizes it at the time. It is only later, much later, standing outside an abandoned cabin, staring at her brother, that Nezuko realizes that it was Senjuro—alongside Mitsuri, who physically manhandled Nezuko to her feet—that pulled Nezuko up from those bloodstained tatami floors. Rengoku steadied her, gave her the strength to stand, but it was Senjuro who gave her fresh floors to stand on.)
So no—the problem was never Senjuro, but Rengoku Senior, and his judgemental, rude comments, a stark contrast to his sons, about how Nezuko would never amount to anything, not while being trained by his failure of a son, and his words against Rengoku hurt more than the slights against herself. But she would grit her teeth and stay silent, stay quiet, furious enough to work harder rather than let it discourage her, needing to prove her worth. Or, rather, needing to show Rengoku that he is not wasting his time, that she is worth the effort.
That she can be useful.
A cold, awful man. The direct opposite of his warm and welcoming sons.
All to say, it was odd and entirely unprecedented for Rengoku to send Nezuko somewhere else for training while he was gone, but they had just begun sparring, Rengoku deeming Nezuko strong, sturdy, and well-enough versed in the basics of sword fighting to start facing a human rather than a dummy, so perhaps it makes sense for someone else to continue the lessons at such a critical time.
(She will be swiftly proven wrong in a lot of ways, but right in some: in that the timing was indeed critical, and that she was in need of a lesson he alone could not teach her.)
The first day Rengoku leaves—the first out of a predicted five—Nezuko arrives at the Stone Mansion fifteen minutes early, lurks outside the looming gates for ten, and after knocking, she spends three minutes wondering if anyone even
heard
her before someone the heavy wooden doors creak open.
The person that opened the gate has Nezuko instinctively bristling.
To be fair, he doesn’t look all that pleased either.
It is the boy—the boy from the well—and Nezuko can see a battle play out on his face about whether or not to slam the heavy gate in her face.
What ends up happening, though, is that he opens it wider, shuffling awkwardly to the side, scowling all the while.
Once Nezuko is inside, he turns, leaving the gate open, and without looking at her, gestures for her to follow. They do not go inside the Stone Mansion, instead skirting around the exterior, and Nezuko looks at the serene gardens with a quiet awe. However, the gardens have nothing on what unfolds around the back of the house. The next breath catches in Nezuko’s throat. While she knew the Stone Mansion was on the outskirts of the Demon Slayer headquarters, butted up against the wisteria, she hadn’t expected the backyard to open up to rows upon rows of the beautiful trees.
The lack of a back fence completely obliterates the need for a gate, but no matter. Nezuko follows the boy through the wisteria trees, past them, into a normal green forest.
The boy continues onward unfalteringly, seemingly knowing where he is going, and they end up following a churning river upstream, the sound of rushing water growing louder and louder until the forest opens up to a stunning, wild waterfall, and a clearing littered with boulders, for some reason. Perched atop the largest boulder is the largest man Nezuko has ever seen, and atop the second largest is a girl Nezuko has never seen before. She couldn’t be much older than Nezuko herself, and was probably younger than the boy, yet she exuded an air that was far more powerful than either of them. Wearing a pristine, pale pink kimono top and a pair of wide, dark pink hakama pants, she looks far more put-together and graceful, too, compared to Nezuko and the boy’s apparel of loose-fitting—space to grow into, according to Rengoku—versions of the regulation uniform, with scuffs and tears in various places from rigorous training.
Based on the boys quiet, “What the—?” Nezuko assumes that he doesn’t know her, either.
But the Hashira—Himejima-sama, if she remembers correctly—does not seem bothered by her presence, so neither of the two ask any questions.
At their arrival, the giant man unfolds himself into an even more giant man, with an intimidatingly tall stature that makes the huge gates far more reasonable, while the girl jumps down from the boulder, silently coming to stand beside Nezuko and the boy.
Himejima is quiet, for a moment, then says, “Twenty laps. Genya-kun will show you the path. Fifty log squats. One-hundred pushups. Two hundred swings of a training sword. You will know you are ready when you can last under the waterfall for thirty minutes.”
Under? Nezuko wants to ask, but when no one else even twitches, she stays quiet, and follows Genya into the forest, crunching on leaves with every step, the girl’s footsteps utterly silent beside her.
The first day, no one speaks but Himejima, and even then, he says nothing else aside from the initial directions. The laps leave Nezuko panting, the log—wider than Nezuko’s torso, something she is somehow supposed to be able to hold and squat down low with—tears up her already-raw hands, as getting a solid grip on the thing near-impossible (for her, at least). The calluses on Nezuko’s hands have only just begun to form after three months of training, and yet they are completely ripped off in one day.
Nezuko can only complete thirty push-ups before her trembling arms collapse, dirt stinging her open wounds. It is humiliating to watch from the sidelines as the boy—Genya—swings his sword with buzzing arms, sweat pouring from his face, out of tandem with the girl’s precise strikes.
Himejima ignores her presence. The stinging of that realization soothes just a little when she realizes he isn’t paying attention to anyone, but it still hurts.
When the two go to stand under the waterfall, however, they’re both washed away in an instant.
Nezuko leaves the forest that day on shaky legs, furiously ashamed of her own weakness.
The second day is much the same, only a little but worse. Himejima doesn’t say anything at all, to any of them, just sits on his boulder, meditating.
Nezuko still cannot finish, Genya is shaky, the girl is firm. Only this time Nezuko doesn’t even make it past the log, her hands a bloody, slippery, splintered mess, enough that Genya actually wrinkles his nose in sympathy when the log slips through her ruined hands and smashes her toes, causing her to bite back a yelp of pain that still slips through.
The girl doesn’t even glance her way.
While the other two do finish, the sword swings have left even the girl’s arms trembling, her palms slightly torn, and as Nezuko silently watches it happen, she plans.
Once again, they wash away under the waterfall.
The third day, Nezuko knows that if she does anything too strenuous with her hands, then her healing will only get set back even further. While calluses only form when the skin is being worked, being strained, it is another thing altogether to not have any skin on her hands, which she is steadily working her way towards.
The other issue is that normally, by the time Nezuko is done with the laps, she’s already exhausted, pushing herself through the woods at her normal running pace even when her legs want to falter. This time, however, as the girl rockets ahead, Genya lagging slightly behind, Nezuko picks up a slow, easy jog. The type of jog she could do all day. And she does—or at least, she does for twenty laps.
By the time she’s done jogging, the girl has already completed the log exercise—Nezuko envies her strong hands—and is onto the pushups, while Genya is just finishing up his squats. Nezuko takes one look at her bandaged hands, blood flecks dotting the surface, and turns away, scanning the clearing. There are boulders everywhere, but she’s looking for—
The river nearby, whose bottom is made of small pebbles. The rocks give way underfoot as she wades into mid-calf deep water, slippery with algae, and it takes all of her focus to not fall.
Once she reaches her goal—in the middle of the river, without anything she might possibly fall on, the fast-paced water rushing along her calves, river-bottom slick underfoot—Nezuko takes off Tanjiro’s haori, fashioning it into what she can only call a sling that is then tied around her neck. She squats down into the freezing water and reaches for the bottom, soaking the bandages and undoubtedly rinsing smeared sweat and blood away off of her palms, and grabs handful after handful of pebbles, loading up the sling, until it feels about the same weight as the log.
Then she begins the squats, after shucking off the wet bandages and putting them in her pocket. If she cannot use her hands, then she might as well continue to strengthen her core in other ways. And as a trade-off, instead of working on her grip, Nezuko works on her balance.
Admittedly, she falls into the river more than once. More than a few times, even, pebbles giving away underfoot, the rushing water constantly fighting against her; all a constant threat hoping to overbalance her. But Nezuko gets back up when it inevitably does, and keeps on going.
When the other two get washed away by the waterfall, they wash right past Nezuko, where she was planking on her side in the shallower water, body perpendicular to the current. She’s only just managed to stay upright, one ruined palm reaching for the sky, when the girl’s body rams into her foot on accident, toppling her in the process, and Nezuko chokes on water as her head goes under.
Once again, Himejima doesn’t give them any instructions.
Genya and the girl immediately take off for the woods, while Nezuko looks at the Hashira curiously. He never seemed bothered—or even like he noticed—when Nezuko did something different: rather, the only change in his expression was to look slightly disappointed when she was forced to quit early.
The phrasing “You will know you are ready when you can last under the waterfall for thirty minutes,” echoes in her mind. And Nezuko wonders.
So she doesn’t join them in their jog, and instead runs through a series of familiar warmups, watching Himejima all the while. When he doesn’t open his eyes, Nezuko heads straight for the waterfall. She’s never tried standing underneath it before, and the first time she does, she’s immediately washed away by the freezing cold water. The second time is not better. Nor the third.
Or fourth, or fifth.
On the sixth, Nezuko picks up a chant, focuses on that “inner flame” Rengoku is always talking about, and stands.
“Keep going, keep going—”
It’s the same chant that she’s been repeating in her head for months, even before Rengoku took her on as a student, as a reminder that Nezuko cannot falter now. Not when she’s on a path— the path, the only path—that could lead her toward revenge. Toward justice.
Toward Tanjiro, perhaps, though Nezuko dreads that meeting with a deeply rooted sense of terror.
“—Keep going, keep going, keep—”
“What the
hell?”
The boy’s voice breaks her concentration and Nezuko washes away, garbling on water until she’s able to get her feet underneath her. When she pops up out of the water, both Genya and the girl are looking at her strangely. It is the first expression she’s seen on the girl’s face.
“What are you doing?” He asks, completely bewildered.
Nezuko shrugs. “I figured it would be easier to stand under the waterfall when I’m not exhausted.”
There is a flick of light, of metal, soaring through the air. A clap, as the girl slaps a hand down on the back of her wrist opposite wrist, capturing the light, and once she peaks under, the girl says, in the softest voice Nezuko has ever heard, “You are not following directions.”
There is something there, in the way she had to flip a coin before saying anything, in the way she speaks like she’s afraid her voice will give out, in the way her voice warbles just a little around the word orders.
“The order didn’t work for me,” Nezuko directs her words to the girl, sure that if she tried to answer Genya she would end up snapping, “So I switched them around. Himejima-sama said that we would be ready once we can last under the waterfall, after all, so I figured it was a good place to start. He doesn’t seem to mind, either.”
In unison, all three glance over at the Hashira, who doesn’t so much as twitch.
The girl turns away first, toward the logs, and Nezuko doesn’t miss how her hands are rubbed raw. Genya follows shortly after, casting one last confused glance at Nezuko, who figures that she’s done enough with the waterfall today, and starts looking around for a shallow place to plank. Perhaps it would help her grow more accustomed to the rushing of water trying to force her off her feet, off her balance, and sweep her away.
Nezuko doesn’t know whether or not Genya and the girl—whose name she really needs to learn—wash out underneath the waterfall. She ends that day with a tiring jog, after all.
The fifth, and what was supposed to be the final day, had Rengoku’s crow not landed on Nezuko’s shoulder that very morning and cawed that he had been delayed, and to keep training with the Stone Hahira, is much the same. Nezuko adjusts the routine to what she thinks would be most efficient, starting with the waterfall and then going to the log—her hands, while not entirely healed, are better than before, and she wraps them in bandages to offer them some protection.
Meanwhile, the other two keep up the same routine, and wash away while Nezuko ends the day with sword swings, her muscles long used to the routine and consistency of the movement, as easy as breathing, even when her body is exhausted.
There is something to it, she notes, about the reliability of a practiced movement, even when she’s exhausted, that proves some of her theories right.
The sixth day, Genya joins her under the waterfall, immediately swallows what looks like half a gallon of water, and washes away. Nezuko watches this happen from underneath the pounding pressure of the ice cold water up until she starts laughing, which—of course—rocks her balance and sends her careening down the river.
The seventh day, Himejima doesn’t show up. They all continue on anyway.
Their quiet routine continues until the tenth day, when Nezuko lasts under the water for thirty minutes, and decides that she is ready to move on to the other parts of the training, and start giving them her all.
The eleventh day, Nezuko joins the girl for the twenty laps, leaving Genya under the waterfall with a snarky remark not to drown while they are gone.
Immediately, Nezuko notices that something is different. About her. There is— there is less resistance as she runs, her body feeling far less weighed down, less exhausted, and instead of being rapidly outpaced by the girl like she had been the first two days they ran together, Nezuko runs alongside her for the first ten laps, before her lungs start to burn and she falters enough that her companion draws ahead.
Very notably, though, she does not lap Nezuko, and they finish within twenty minutes of each other.
Kanao ends up remaining under the waterfall for ten minutes, and Nezuko for twenty-three, while Genya completes his laps.
On the twentieth day, Genya stomps toward Nezuko with a familiar fury and grabs a fistful of her shirt, shaking her with every word, “How did you do it!?”
“Do what?” Nezuko snaps back, even as she allows his fingers to remain where they are.
“Stand under the waterfall! Improve so fast! Become a Tsugoko without any training! Any of it!”
Out of the corner of her eye, Nezuko watches as Kanao twitches forward, then pauses. She flips her coin and, upon checking its results, stays still, although her brows make an aborted move downward that smoothes out again after a second.
Genya shakes her again after noticing her wandering attention, his face bright red and furious. “You don’t think I’m even worth your attention, huh?” He snarls, spit flying everywhere, “Stuck-up brat.”
He lets go of her shirt with a scoff, eyes rolling. It is his mistake, though, because Nezuko—in a perfect mimicry of him at the well—punches Genya in the face. She, however, isn’t about to apologize. Then, in a slightly taller mimicry of her, Genya surges forward, tackling Nezuko to the ground, where they roll around furiously, with none of the finesse of swordsmen. It isn’t play-fighting, either. Nezuko’s nails gouge across Genya’s arms, his knees jabs into her gut, and her fist collides with his dumb, stupid, ridiculous head, over and over and over again.
There is dust and dirt in Nezuko’s mouth, which she spits out—spits at Genya—and when he tries to push her face to the side, she bites him. A pile of fists and teeth, punches and scratches, all with the intent to cause genuine pain, even as they both refrain from serious injuries.
All the while, Genya is shouting things that don’t make sense at all.
“How come you get a breathing style?”
Nezuko doesn’t think she “has” one—Rengoku has only been teaching her the basics of swordsmanship so far.
“Think you’re better than me? Huh? Huh!?”
Nezuko thinks she is the worst, actually.
“What is so special about you? Why—”
Special? She’s the one who stole someone else’s destiny.
Nezuko stops biting his hand—the hand he’s trying to rip away from the brutal trap of her teeth—just to snap right back.
“Screw you! What the hell are you even talking about? You’ve got the strongest Hashira training you—”
“You’re a fucking Tsugoko. I can’t use breathing styles, so Himejima-san is just—just—”
“Just what?” Nezuko snarks, “Pitying you? You think a Hashira has time for pity? Idiot!”
“You don’t know anything!”
“Because you don’t say anything!”
“Ha— like you would even care.”
“I would! But because you’re too much of an idiot to realize I’m not trying to fucking fight you—”
“We’re fighting right now!”
“Because you started it!”
Something hits Nezuko’s cheek. It stings. Another stinging tap, on her shoulder, but she doesn’t stop fighting until a barrage of cold, wet pebbles smacks against both her and Genya. The rocks sting, a not-insignificant force behind them, and as one, they look over to see the girl Nezuko still doesn't know the name of standing beside the river, a handful of wet river-pebbles in either hand.
The expression on her face—something Nezuko does not know her enough to describe—falters, for a moment, and she opens her mouth to say something, probably, but all that comes out is a very quiet, very soft, and incredibly nervous, “Stop.”
Slowly, Genya and Nezuko exchange a glance. The instant they look at each other again, though, the next handful of pebbles is thrown. More firmly this time, but still very nervous, she repeats, “Stop!”
“We aren’t fighting anymore!” Genya explodes, while Nezuko explodes in a similar fashion, although far less aggressively.
“Who even are you?”
A pause.
Genya nods in agreement, his anger easily redirected from Nezuko to the person throwing rocks at him, “Yeah! Who are you? I’ve never seen you before.”
Her free hand darts towards her pocket, stalls, then falls. “Tsuyuri Kanao,” she introduces, then looks expectedly at Nezuko and Genya. Or, well, Nezuko thinks she looks expectant.
“Kamado Nezuko.”
“Genya.”
When two sets of eyes study him, Genya’s face reddens, though with embarrassment or fury… who knows. Not Nezuko, that’s for sure, and maybe not even Genya. “What!?”
Nezuko looks away, back toward Kanao, who she juts her chin out at, narrowing her eyes, “Why did you throw rocks at us?”
…
“You were fighting?” A question, rather than a statement, even though they had most definitely been fighting.
“Yeah, but—” Genya pauses, takes a sideways glance at Nezuko, then looks suspiciously back at Kanao as she starts to raise the other handful of rocks, “We weren’t going to hurt each other. That badly. Probably.”
“Gee, how confident—hey!” A pebble strikes Nezuko, and Genya laughs. Then one hits him, too, so Nezuko laughs, until a pebble hits her and her patience finally wears thin.
She doesn’t look at Genya as she stands up, even though she offers him a hand, which he takes after a moment.
They all stare at each other for a while, silent, until Nezuko declares, “I’m going to throw you in the river.”
Kanao looks back at her with wide eyes.
She doesn’t get thrown in the river, mostly because Nezuko and Genya—even after reluctantly teaming up—could not catch her, but when they all collapse onto their backs on the well-trodden dirt, peels of laughter escape from Nezuko first at the absurdity of the situation. As Genya joins in, and Kanao’s shoulders silently shake, Nezuko lifts a fist. From either side of her, the two watch her closely, their laughter stilling.
“We should be friends,” is all Nezuko says.
An awkward amount of time stretches by before Kanao raises her fist, too, and bumps it against Nezuko’s. She then props herself up on her other arm to look across Nezuko—who turns her head, too—to stare at Genya expectantly.
He stares back at their serious faces, utterly defiant, before Nezuko says, “I won’t tell Himejima-sama that we fought if you become our friend.”
A third fist raises into the sky without hesitation, bumping against Nezuko’s.
She smiles.
(They’re inseparable, after that. Or, as inseparable as they can be. They train with their teachers when they can, but with each other when they can’t. When Genya starts growing at unexplainable rates, he folds like wet paper under the force of their combined stares, but all Kanao does is pat him on the shoulder while Nezuko congratulates him on his growing strength. When Kanao never explains her coin, but starts using it less and less anyway, Genya and Nezuko exchange private, triumphant smiles behind her back. And when Nezuko tells them about her family, about her nightmares, a large and small hand, equally calloused, take hers, and holds tight.
They take on the Final Selection together, take on missions together, take on everything they can—even a Lower Moon—as a team, until Nezuko goes with the wrong team, and ends up on her own. When she limps back to headquarters after being missing for five days, it is their arms that envelop her first, clinging on tightly, as though they never wanted to let go. Genya’s eyes hold promises of protection, of trust, while Kanao’s hold a silent threat to never dare scare her like that again. While Kanao may not have the words to describe how she feels, Nezuko knows her, and she knows exactly when her expression means.
At the sight of Nezuko’s eyes, though, holding only tears and an odd sort of grief, they soften, holding her tight—only letting go when the Master’s crow calls for her. Even then, it is reluctant.)