wandering road, wherever you are

By: Aviantei

Soulmate AU:

"Intertwining Lightning Bolts"

Soulmates are real.

Oh, sure, people will pretend like they aren't, treat them like some sort of myth. Soulmates are spoken in the same dismissive way as demons, as other fantasies—as if things like that would stop existing just because there are electric lights and not as many people fear them anymore. There are still people born with the name of their soulmates etched on their skin in irrerasable marks. Kaigaku would know, since he can see them.

They're not obtrusive in the slightest, and their locations vary, so it's not like they're easy to spot. But not everyone has a mark in a place that's easy to hide, so every now and then, Kaigaku gets a glance: just tiny little imprints of kanji, on someone's cheek, on the back of their hand. On occasion, a couple with their marks in same places on their bodies, the characters shimmering in colors other than their default black.

Just like not everyone can see the soulmate marks, not everyone has them, either—and Kaigaku falls into that category as well. It's never really bothered him, anyways. All the way back at the temple, just a couple of the kids had the marks. And when it came to being on the streets, it was a bit of a relief, not having to worry about someone getting messed with just because they happened to have matching marks, not having a weakness to exploit. Even beyond that, it's not like Kaigaku's ever thought hard about being in a close relationship—romantic or otherwise—before. Survival's always been the priority.

Except one day he gets picked up by Kuwajima Jigorō, and survival gets a little bit easier. Kaigaku was already interested whenever he realized this was an opportunity to join the Demon Slayer Corps, but it's nice to not need to worry about scrambling to live. Oh, sure, he's still going to be vigilant, and he's damn sure going to give his new training his all, but having food and shelter isn't going to be a constant battle. Maybe he can find something sort of close to peace for a while.

And then he sees them, and Kaigaku stills. Aside from the pale lilac to deep violet gradient of their haori, their appearance is unassuming, the type of person he'd maybe pick the pocket of but wouldn't be his first choice. Except that's a perspective he doesn't need to have anymore, and this new perspective is…something.

They're attractive, this person with their braided hair and deep brown eyes—and Kaigaku's never thought that about someone else before. He likes the way they look, wants to study the shape of their jawline, the curve of their neck. There's a flush creeping over his face, and there's even a strange tingling sensation at the back of his neck that almost tickles underneath his choker. His stomach flips, his chest clenches, and Kaigaku tries to get himself the fuck under control. Is this what people who have soulmates feel like whenever they meet each other? Kaigaku imagines that it must be close.

The person stares back at him, a faint tinge of red ghosting over their cheeks—and both they and Kaigaku snap to attention as Kuwajima—Sensei, it's Sensei now—says, "This is my other apprentice. Child, show some manners for once and introduce yourself."

"My name is Rairi," they say, sounding a bit flustered by the fact. Kaigaku tries to imagine which kanji that uses, is caught up in the fantasy of looking over himself and seeing the characters on his skin, though he knows he won't find them. "My condolences if Sensei picked you up at random, like he did with—oh, come on!"

It takes Rairi—come on, which characters is that?—rubbing at their shoulder for Kaigaku to realize that Sensei must have whacked them, and he didn't even see it happen. He already guessed as much, but Sensei is not someone to fuck with. Deciding to make the best first impression possible, Kaigaku dips his head in a bow. "It's nice to meet you. My name is Kaigaku." Those words alone feel wooden in his mouth as it is, but Kaigaku still feels flustered, so he adds, "I'm in your care, Rairi-senpai."

"Ah, right. Looking forward to training with you, Kaigaku."

Rairi bows as well, a little bit deeper than Kaigaku did, and the motion's enough for their braid to slip over their shoulder. The fact that they're not looking at him is a bit of a godsend, because it's the first time he's ever felt embarrassed about someone calling him by his given name with no honorifics, and his new senpai doesn't need to see his face burn red.

And then he gets to experience a hit from what must be Sensei's cane (come on, when the fuck did he even move?), which kicks Kaigaku's survival instincts so far into high gear that he can't think of anything other than getting ready to fight. Except when he turns, all he gets is the old man giving him that wily grin, and his well-honed fight instinct tells Kaigaku to not even bother, because it's just going to end in pain.

"There, you've got the pleasantries taken care of," Sensei says, waving for Kaigaku to follow. "Now let's get you into a bath and get to work on putting some meat on those bones, Boy."

Kaigaku's stomach grumbles at the idea of food, and a bath seems like an unnecessary luxury—but this is life now, where these strange things are going to be part of his ordinary, he supposes. So he thanks Sensei for the bath and scrubs himself down, mud almost slaking onto the floor. Kaigaku makes sure he's clean and presentable, and maybe takes a little too long checking over his body for anything even resembling a mark that wasn't there before. But Kaigaku's soulmate-less, just like he's always been, and he's just a dumbass.

He realizes far too late that, while he was gawking, he was still a scrappy, dirty mess from the street, and that was his first impression, no matter how polite he was, and Kaigaku just ducks his head under the water and screams for a bit.

You don't have a soulmate, you never will, and that's fine. Fucking prioritize.

You're here to learn to fight, to learn how to survive. You didn't come this far just to get undone by your feelings!

Kaigaku does not have a soulmate, but Rairi does. In fact, they have at least two. The marks are both on their left hand, one pressed into the wrist, right against their pulse, the other on their ring finger, resting right above their palm. Kaigaku's just caught glances of the marks, never close enough to read the delicate characters, but he's seen enough of the things to recognize them even with that little to go off of. He doesn't know why he's bothering to be curious; he doesn't have marks in either of those places, so it's not like his name is going to be pressed into Rairi's skin just because he manages to catch a closer look.

He wants to know, though. Who are these people that are going to—if the legends are true—complete Rairi, that are meant to be a part of their life? Are they going to be lovers? Close friends? There are so many options for what being a soulmate consists of, so much mix of truth and myths lost to time. There are also people who work to find happiness for themselves, rather than following anything that seems predestined, and then others who treat soulmate marks as law. Where does Rairi fall in that scale? Regardless of the names on their finger and wrist, does Kaigaku stand a chance?

Why does he care?

As he learns the basics of swordplay, Sensei sets Rairi and Kaigaku to spar with each other. Kaigaku's learned a lot, so he can put up a fight—but Rairi beats him all the time. It's beyond frustrating, so he insists on sparring more, and Rairi faces his challenges without missing a beat. It's one day when he's gotten knocked on his ass and Rairi offers to help him up that he at last sees their marks.

Kaigaku can't read the one around their wrist, because he doesn't know how. It's a foreign alphabet, one that Kaigaku didn't have any reason to learn. So, what? There's just…some foreigner that comes in and sweeps Rairi off their feet? The one good thing about this situation is that he can read the name on Rairi's finger, since it's in kanji he recognizes: Zenitsu, it says, a name to put on this person that will appear in Rairi's future.

Kaigaku's scowl has nothing to do with the latest entry in his near infinite list of losses as Rairi helps him up. The sensation of their skin presses into his, and it's just as overwhelming as the first time he saw them. Why is this affecting him so fucking much? Rairi is just a person, the same as the dozens of others he's met in his life. It doesn't matter that they're attractive, that they're stronger than him, that they have a nice laugh, that they're always giving training their all.

Except one day after lunch, Kaigaku catches a glimpse of something dark on the back of Rairi's neck as they wash the dishes together. It was just for a moment, when they turned to call a response to Sensei and their braid swayed. It could be nothing. A shadow, a mole, a trick of the goddamn eye. But Rairi already has two soulmate marks, so it's not like a third would be that far out there.

"Rairi-senpai, hold still," Kaigaku says. Rairi makes a confused sound, but complies anyways. "I thought I saw something on your neck. Can I try to get it?"

"Huh? Yeah, go ahead." And Rairi even shakes their braid over their shoulder to help, and Kaigaku has to hold back his gulp.

Sure enough, right in the center of Rairi's neck is a neat little pair of kanji that spell out a name—and it's his. Kaigaku's so in awe that he brushes his thumb over it, just to be sure he's not dreaming, and Rairi shivers, a soft little gasp spilling out of their lips that sounds so fragile that Kaigaku's worried he hurt them. He snatches his hand back to his side, his fingertips still tingling from the contact, and Kaigaku has the perfect view of the kanji of his name rippling in a deep cobalt blue when the characters were pitch black just seconds before.

"Rairi-senpai," he says, his voice a whisper, "do you believe in soulmates?"

"Oh," Rairi says, sounding faintly dazed. "Is that what these are, then?" They lift their left hand, the sleeve of their haori slipping enough to expose the letters along their wrist. They run their right index finger over those first, then the kanji on their finger, and it occurs to Kaigaku that Rairi can see them, too. Have they not known; have they not been searching for the owners of those names? They reach back, their fingers grazing over Kaigaku's mark on their skin. "Is there another one back there, Kaigaku?"

"Yeah." Gods, he sounds so weak, but he has to try to keep it together. There's not going to be an easy way for Rairi to look at the thing themself, so it's Kaigaku's job to help out. "I—I think it's mine, but there should be—" He swallows, reaches back to his own neck, the familiar texture of his braided cord meeting his fingers. "I thought I didn't have any," he admits, "but if it's mine, then we should match." Rairi's turned around, looking up at him, and Kaigaku doesn't know what to do, because as much as he's fantasized, he never thought—

"I can check if you want." Well, at least Rairi sounds as stunned as Kaigaku does, so they're in the same boat there. Kaigaku nods his approval, turns around, his fingers already untying his choker and securing his magatama in his palm. It's just an accessory, but he feels somewhat vulnerable with it even just loosened. Or, well, he gets to feel vulnerable for a handful of seconds before Rairi's fingers press onto his skin, and Kaigaku shudders.

It's not a bad feeling in the slightest; in fact it's wonderful. It's just so goddamn overwhelming, even more so than the surge of emotion that caught him whenever he saw Rairi for the first time, more than the casual contact of sparring and helping each other up, more than when their fingers brush together as they wash up the dishes of their meals. It's warm, not just at the spot where Rairi's touched, but all the way through his body, an echo of feelings and completeness that he's never felt before. It's something intimate, and, if Rairi felt this much whenever Kaigaku touched their mark, he almost wants to apologize for doing it without permission.

On the other hand, he also wants to reach out again, because Rairi's touch is lingering far longer than Kaigaku's had, and he wants them to feel this sense of belonging, to feel secure in the fact that their souls fit together. "It's you, isn't it?" he asks in a whisper, though in the deepest part of his being he already knows. "It has to be you."

"Yeah," Rairi says, their voice just as soft. "It's me." They pause as their touch slips away—no longer pressed to the mark but still lingering on his skin. "It turned purple. Is that normal?"

"You don't know?" How can someone who can see the soulmate marks not understand them, not at least seek out information on what the names are? Kaigaku did all that, more passive than active at times, and he doesn't even—well, at least he was damn sure he didn't have any. How could you live your whole life with two names printed on your hand and not know what was going on?

"I mean, I'm familiar with the concept? I just…don't know how they…work, instead of stories…"

Kaigaku turns back around to face Rairi, catching the blush on their face that must match his own. "It's normal," he says, and Rairi looks relieved, though they keep glancing back to the fingers that were just at the back of Kaigaku's neck, as if impressed their touch could cause such a change. "It's like…there are just so many names out there, and just so many places, I guess? If the mark doesn't change when someone touches it, then you know they're not your soulmate."

"That…makes sense," they say. Their hand reaches back to their own matching mark, where Kaigaku's name is on their skin. "If yours changed, then mine changed, too, right? Is it purple, too?"

Kaigaku shakes his head. "It depends on the person, though no one ever figured out why. One of those things that got lost in myth or whatever." Rairi's looking up at him, the curiosity clear in their eyes, and Kaigaku glances away, his embarrassment more pronounced than ever before. "It was a dark blue. Like…" He rolls his choker cord still between his fingers, realizing it's the perfect comparison, and Kaigaku holds up the accessory for Rairi to see. "Like this, though with that more blackish edge to it?"

Rairi nods, a faint smile on their lips, and their hand tugs up the end of their haori, where the faint lilac bleeds into a deeper violet. "I'd say the same about yours. It's close to that." Kaigaku's watched Rairi wear the haori day in and day out since he's arrived, and it's the first time he considers the shade, imagines the blend of color shimmering over the characters for Rairi's name—and, fuck, Kaigaku has a soulmate; what's he supposed to do now? "Do you mind?" Rairi asks, their hand already reaching back out, and Kaigaku nods. "It felt…nice."

Nice as a word that just covers so much of what it feels like, but Kaigaku understands. He lets Rairi press their fingers back against the mark, and that sensation washes over him again. Now that he's had the chance to get used to it, Kaigaku feels a little bit more at ease. Rairi's still blushing a bit, and the red burns all the way up to the tips of their ears whenever Kaigaku's fingers brush across the side of their neck before his touch presses into his mark on them again, and Rairi sighs. Kaigaku's voice intermingles with theirs, because the shared sensation resonates between them, and he's back to feeling overwhelmed all over again.

When it comes to how it feels to connect with your soulmate, that's something where even the older stories vary on—but Kaigaku stops giving a shit about any of that, because he's experiencing it right now. Rairi's presence is warm, and it sinks into what feels like a box in his heart and fills him up. In time, it's not just the coursing of electricity that reaches him, but he can also sense that Rairi's feeling it, too, their curiosity mingled with their embarrassment and happiness, their emotions bleeding into memories.

Kaigaku catches fleeting images of familiar places—the peach orchard, the nearby town, training with Sensei, Kaigaku himself painted under the lens of Rairi's perspective—and then things slip further back. Rairi bouncing between shopkeepers, Rairi before they were even Rairi, Rairi nameless—no, that's wrong. Rairi with a different name, and then the world is different. Kaigaku hears flickers of a language that he doesn't recognize but understands thanks to the soulmate connection, but people look different, there's a school(?), a family, so much that Kaigaku understands without needing to try but still needs to process—and then it all comes crashing together in a deafening shriek, an impact, tears, pain, and it's finally the image of someone that looks an awful lot like Rairi but not quite (Jaden, older sibling) with their head spilt open in a bloody, brain exposing wound that at last shocks Kaigaku enough to pull away, Rairi's horror from that moment imprinting on him and leaving Kaigaku gasping for air as tears leak down his face for the first time in ages.

Rairi doesn't fare much better, them sobbing as they look up at him—and it occurs to Kaigaku a bit later than it should have that if he saw Rairi's memories, then they saw his, and there's just one thing in his past that's worth that kind of horrified reaction, and pure shame rushes up to replace every good and connected feeling he had not even seconds prior.

His jolt knocked Rairi's fingers away from his mark, but they're still close enough for their hand to try to cup his cheek. "Kaigaku—"

"No!" Kaigaku smacks their hand away, simultaneously craving the reassurance of their touch and terrified of feeling their emotions bleed into him in the utter disgust and contempt they must have for him now. "Don't—Forget it—"

"Kaigaku, it's okay, I'm not judging you. You—you were a kid, your life was in danger, you didn't have a choice—"

"What do you even know?!" He's shouting, his voice echoing off the walls. Kaigaku aches for the grip of a bokuto in his hands, for the burning satisfaction of training, of pummeling a practice dummy into the ground—anything to redirect this anger boiling out of him. "Are you going to tell me that it's fucking okay? That I let the lot of them be killed so I could live?! I just saw what you had. Don't tell me, with your cushy little life, that you can even attempt to understand—"

Rairi breathes, the familiar hiss of Total Concentration a precursor to their rapid movements. One hand fists in the front of Kaigaku's kimono, the other slamming down onto the back of his neck. The precursor to the memory he was in beforehand rushes into Kaigaku's mind, Rairi (Robin) about to cross a paved road near the park, glancing both ways before darting across, even though they're not supposed to on their own, and that's why they're in the wrong place at the wrong time when the hulking mass of metal comes barreling towards them, the one that crashes into—

Rairi's guilt overlaps with Kaigaku's own, that consuming and awful feeling lingering even as Rairi pulls back, their face twisted into a snarl. "Do you wanna say that again?" they hiss. "Do you want to act like you're the only one that hasn't gotten someone killed—"

"You didn't make a choice. You didn't have someone say to you 'Hey, you can walk into this street and either you or Jaden will die, so choose,' and then decide to keep yourself alive!" It occurs to Kaigaku that maybe it would be better if he didn't have a soulmate, because no one should have their soul bound to him and all his selfishness, betrayal, and aggression. "Forget about the marks. I don't deserve that." Rairi makes a disgruntled sound, but Kaigaku pushes onward. "It's not like you don't have choices for soulmates. Even if you didn't, I wouldn't force you to put up with all of this."

"Fucking excuse you?!" Rairi doesn't tend to raise their voice, but this time they shout back at him, the already present anger twisting their face further. "You don't get to make decisions for me!"

"If you understand so goddamn much, then there's no reason you would ever decide to pick me—"

"If you don't want to be with me because of yourself, fine, but don't you dare try to act like there's no way I could ever not want to—"

"That's enough!"

The sound of Sensei's cane hitting against the floor silences them both in an instant. If Kaigaku's being honest, he'd forgotten that he and Rairi were supposed to be taking care of the dishes; the moment he saw their mark (his mark on them), the world just felt like the two of them with nothing else.

"I wondered what could be taking you so long to come to training when you both know the routine by now," Sensei says, his voice so calm it's terrifying. "And what do I find? My apprentices screaming at each other, unable to finish something as simple as cleaning up after themselves." Sensei steps forward, shorter than them both but no less capable of being able to get both Kaigaku and Rairi on the verge of cowering for forgiveness. Sensei's gaze snaps onto Rairi, and Kaigaku tries to pretend that he's not relieved. "You're the senpai, Child. Explain."

Rairi flinches, their gaze boring a hole into the ground beneath their socks. "We're soulmates," they say with just the faintest traces of hesitation, their voice projected loud enough for Sensei to hear them clearly. The bluntness of their words sends a surge of happiness through Kaigaku that he attempts to suppress. "We…had a disagreement about it."

It's a risky explanation. There's just so many people that even still believe in soulmates—but Kaigaku supposes if anyone's going to acknowledge it, it's going to be the man teaching them how to fight demons. Sensei doesn't attempt to argue, his gaze combing over them both. "Both of you, sit." There's no hesitation; Kaigaku and Rairi both settle themselves into the seiza position on the floor, and Sensei steps before them both, his presence as indominable as ever. "How long have you known?"

"We just found out," Kaigaku says. His voice has nothing close to Rairi's confidence, but Sensei nods in understanding, so he at least heard. "I don't know if you know, Sensei, but you can share memories across marks, and…" His words fall short; since Rairi knows, Rairi could say it right here, could say that Kaigaku's already given into a demon once, could say that he's not worthy to be in the Demon Slayer Corps. A few sentences would be all it takes for every last bit of the security of the home Kaigaku's had for the past few months to disappear, just like that, and wouldn't that be just the best possible way for everything to end, with him back on the streets again?

Except Rairi doesn't say anything about it, though it's obvious they're still upset: their expression trying to stay calm but letting a sharp crease form in their brow, their shoulders tight, their hands fisted in their pants. Sensei hmms. "I'm well aware of what you can do with marks, boy," he says, sounding almost wistful. "Even so, that can be an intense experience for soulmates who have just found each other, and even more so depending on how far back you've gone.

"Still, the decisions you two end up making will be up to you, and it's not like my lecturing you will do much, so let this sensei of yours offer some advice: even if your souls help complete each other, you're still responsible for working together and putting in the effort to build that relationship. A soulmate bond doesn't make everything perfect or easy, but the work is always worth it." There's an almost faraway look in Sensei's eyes, though neither Kaigaku nor Rairi dares to ask if he's speaking from experience. "That said, regardless of what happens between you two, you'll still be expected to train and work together as normal. Do you understand?"

In tandem, Kaigaku and Rairi say, "Yes, Sensei."

"Good. Now finish up those dishes and go outside. We have a lot to cover today."

And with that, the matter is as settled as it's going to get.

Except the matter doesn't feel settled, not at all. Now that he's gotten a taste of what being connected to your soulmate is like, Kaigaku can't stop thinking about it. If it weren't for the fact that Rairi had seen everything, if they didn't know about the past that Kaigaku had long ago decided not to share with anyone, would he be enjoying that connection now, would he be reveling in having someone who fills his heart up so much?

Because that's what Rairi does: they're a puzzle piece that fits right into them, an excellent match for all his impatience and irritation, and god he wants to feel their touch on the back of his neck again, wants to feel whole and complete, so why did he have to dive in so deep that he can't even take it back?

Except it's better that it happened now, sooner than later, because that way he didn't have to get attached. It won't hurt when they abandon them later, because they've already moved on now, and Kaigaku won't have to have his heart ripped apart like he did after everyone died at the temple.

Just thinking about it sours his mood, and Kaigaku throws himself back into training, not speaking other than to respond to Sensei's direct orders and questions. Skipping meals and chores is not allowed at the Thunder Estate—but other than that, he's either in the orchard, getting extra reps in or sleeping in his room.

He tries not to look at Rairi.

It doesn't work.

Just like before, whenever they're in the same room, he's drawn to them. Are they even more beautiful to him now that he knows they're his soulmate? It sounds like the sort of shit he hates, but he can't help but think it. He's smitten, and it feels awful and wonderful all at once, and it's all the worse because he doesn't deserve them, he's never deserved something like this, and they're going to realize it sooner or later.

(Rairi can't rip Kaigaku's heart out if he does it to himself first.)

So he keeps trying to avoid them, which works about a week before one morning he goes to the clearing in the orchard to train and finds Rairi sitting on the rock there. Kaigaku freezes, his mind unable to decide if he should run away or fight or just stay stock still, as if that will make Rairi not able to notice him in his dark kimono in the middle of all the trees.

They do notice him. Of course. Their expression is unreadable.

"I'm not going to force you to talk," Rairi says, not moving from their position. Kaigaku doesn't move, either. "I just wanted to say that when you're willing to have a conversation with me, I'll be ready."

They wait a few moments, just in case Kaigaku has anything to say. He doesn't. Or, rather, he does, he just can't bring himself to say anything. When that becomes clear, Rairi hops off the rock, heading towards him with wide strides—no, heading past him, back out of the orchard and towards the estate, leaving Kaigaku alone with his thoughts once more.

The look of disappointment on their face is one he can't forget anytime soon.

Rairi maintains their respectful distance. Sensei doesn't push for anything other than continued training, chores, and meals together. The Thunder Estate is quiet, though Kaigaku's mind hasn't shut up for the past week. The back of his neck prickles, as if to condemn him for ignoring the person that's supposed to complete him, and Kaigaku has to resist the urge to scratch off his own skin.

It wouldn't work, anyways. He's seen people who've tried. Nothing can make the marks go away, not even death.

It's not until Kaigaku's heading out of the bath—after waiting to hear that Rairi's returned to their room, just so he can continue avoiding them—that he crosses paths with Saori, the head housekeeper of the Thunder Estate. She's old, but she's not to be fucked with, though in a different way than Sensei, so Kaigaku's shown her the respect she deserves for the most part.

The reminder that he's at the Thunder Estate and safe because of the generosity of others was a good reminder to keep in line, and Kaigaku's made a point of not pissing Saori off since.

Which is why the sight of the woman herself standing in the middle of the hallway and staring right at him is downright terrifying. The feeling is further accentuated by the fact that, as Kaigaku, gets closer, Saori shows no sign of moving out of the way. Fuck, am I in trouble? Did I do something stupid when I was cleaning out the tub? Since Kaigaku's maintained the appropriate level of respect, that's his best guess for why he could've upset Saori so much.

Well, if he's in trouble, might as well accept it instead of attempting to run away. So Kaigaku comes to a stop, dips into a bow deeper than the ones Sensei lets him get away with, and asks, "Yes, ma'am?"

"You're being a fool," Saori says, which is not what Kaigaku expected to hear, but he's not about to protest. "If you think that avoiding Rairi-sama is going to do any good, then you're mistaken. Such feelings are best faced head on." Oh, this is about the soulmate situation. Fuck, does everyone know now? "I have lived for a long time being able to see the marks, Kaigaku-sama. In my observations, everyone who doesn't face themself on the matter does not have a good experience."

Kaigaku would argue that most of his life he's spent without having a good experience, but even he doesn't have the guts to get into a fight with Saori on the matter. Instead, he grunts, which can be taken as either a dismissal or a reluctant acknowledgement, and even Kaigaku isn't sure which one he means it as.

"If nothing else," Saori continues, "you and Rairi-sama will be under the same roof for the next few years. I suggest coming to a compromise." And her piece said, the woman turns on her heel and walks off with an impeccable sense of grace, leaving Kaigaku in the hall and feeling just as much like the fool Saori has accused him of being.

Kaigaku does not act on Saori's words right away, of course he fucking doesn't, but at least it's not because he doesn't think she has a point. He knows she has a point, but that doesn't make it any easier. Rairi may have said they were willing to talk, but what if he waited too long and they've just…given up? Kaigaku would've, just decided to wash his hands of all of it and moved the fuck on.

And yet, here he is, wanting to try.

He feels like he'll regret it for the rest of his life if he doesn't try, and Kaigaku has enough to regret already.

"Rairi-senpai," he says that afternoon after Sensei dismisses them from their training, "spar with me."

There's a beat where they looked stunned, and Kaigaku's bracing himself for the rejection already. But it just a second longer before the smile, adjusting their grip on their bokken and say, "I was starting to think you'd gotten tired of fighting with me after all this time," which is kind of funny since the whole reason they hadn't been talking was because they'd fought, just in a different sense. And yet Rairi raises their bokken, their form as precise and graceful as ever. Sensei must feel that they need some alone time, because he heads inside the house, rather than sitting on the enka and observing like he so often does. "Careful, Kaigaku. I'm not planning on holding back."

If this were a couple of weeks ago, Kaigaku would want to hear those exact words, and nothing else would've mattered. Rairi was—and still is—Kaigaku's goal post when it comes to training, and he can't catch up if they're going easy on him. Now, he's still glad to hear so, but he can't help but feel self-conscious about how the request for a fight is little more than a thin-veiled excuse to have contact without having to start right out by discussing feelings.

So they spar, neither of them saying a thing. Like always, Rairi waits for Kaigaku to make the first move—and his bokken moves in a burst of speed, one that Rairi parries and responds to, setting them off. It's a simple exchange, one without any Thunder Breathing forms to intensify the battle, but the physical activity feels good, makes Kaigaku feel comfortable in a way that nothing else does. The two of them get into their rhythm, exchanging blows for a few minutes before Rairi manages to sneak their weapon into an opening Kaigaku left, cracking their bokken against his knuckles and making him drop his own. Kaigaku curses, shaking out his hand as if that's going to do anything to make it better, and then he's forced to admit he can't stall much longer.

Just like Rairi waits for Kaigaku to make the first move, they wait for him to speak the first word, the gaze in their deep brown eyes expectant, and Kaigaku can't get rid of the urge to kiss them, right then and there.

But I can't let that happen. If he does, it'll be too late. But he also can't stand the thought of never talking to Rairi again, so he needs to find a compromise both his heart and his mind will be happy with.

"Look," he says, forcing the words out of his mouth. He'd rather pull off each of his fingernails one by one, but Kaigaku perseveres. "I don't want to ignore you." They're already far too important to him for Kaigaku to be able to stand that prospect. "But I can't… I'm not… The soulmate stuff…" It's more than clear to him that their soulmate connection is a romantic one, which he can't control, but everything that entails is just too much—

Kaigaku's discomfort must be tangible in some way or form, because Rairi just nods, despite Kaigaku not finishing his sentence. "Kaigaku," they say, and it's almost unbearable how wonderful his name sounds in their mouth, how much he wants to hear it over and over again, "do you need to set a boundary?"

His face screws up in a very different configuration than the way it was screwed up before. "What's that have to do with anything?"

"What do you mean—oh, right, Taishō Era." Rairi's exasperation melts away into understanding. It must be a word that has a different or new meaning in their time, and, given the circumstances, Kaigaku can't help but think it's a miracle they can communicate at all. "I guess what I mean is…rules. Do you need to set rules that I can follow so you're comfortable?"

That concept makes much more sense, even if the idea is a little bit foreign. Kaigaku isn't used to having his requests respected in such a way, but he knows, if anyone will follow through, it's Rairi. "Alright, let's do that, then." It then occurs to Kaigaku that he has no idea how to do this boundary thing in the first place. Admitting that he's clueless stings his pride more than anything, but it'll be worth it in the long run to not have to dance awkwardly around Rairi anymore. "What sort of rules should we make, then?"

In the end, Rairi offers plenty of suggestions, adding the reminder that they can add or change things later if need be, and from there, Kaigaku just wants things to go back to normal.

Things from there are not quite normal, but they're close enough. Meals and training are a bit less awkward, and he and Rairi even chat most times they interact. The two of them spar together, senpai and kōhai, and Kaigaku thinks they might be able to even consider themselves as friends, which he's more than happy with settling for.

(This is, of course, a lie, but if he says it enough times, it should be true, right? Plenty of soulmates are platonic, and there's no reason that can't be what their bond is, except for the fact that it's very much not.

Kaigaku has chosen to ignore this fact for all it's worth.)

Too bad for him that settling is near impossible. Kaigaku's always been a selfish little shit, and this is no exception. Being around Rairi and being on good terms with them again is just a reminder of how attractive he finds them, and every little moment just intensifies those thoughts. He doesn't say so, since that would be a violation of the rules he set up—no talk about the prospect of romance—and he kind of feels like an idiot for that one, yeah, but it's all for the best.

If all goes to plan, just being friends with Rairi will be enough for them to realize how awful of a person he is, how much he's just not fucking worth the effort. While it would be easy to be a dick on purpose to that end, Kaigaku is certain that will just piss off Sensei in the process, so he shelves that idea. Just being himself should be more than enough.

But as the days melt into weeks, Rairi hasn't changed their mind—but Kaigaku is starting to change his. Are the weeks idyllic with no issues? Of course not. He and Rairi are different flavors of stubborn, and that means they disagree and bicker—but not on the level of their blowup upon discovering their soulmate marks. At the end of the day (sometimes after a lecture by Sensei), they compromise, and it fills Kaigaku's heart with a funny sort of feeling.

It takes him far too long to recognize that feeling is hope.

Their growing friendship means that, while not all the time, he and Rairi often spend their days off from training together, or at least parts of them. A few months out from the soulmate reveal, they agree to take their pocket money (given once a month by Sensei, a few coins snagged from doing extra chores from Saori now and then) and head into town.

The weather is beautiful and, while it's nothing luxurious, it's still nice to get a change of pace every now and then. After wandering around for a bit, they stop to get some food, Rairi offering to pay and running ahead before Kaigaku can argue otherwise. At first, the (poor kid in the slums) miser in him is grateful that he can hoard his own cash a bit longer, then he feels a bit guilty, and then all thoughts of any kind fly out the window as he glances over to where his senpai has gone.

For that one instant, Kaigaku gets a look at Rairi as they smile, trading a few coins as payment for some yakitori skewers. Kaigaku hesitates a moment, but in the end he tucks his finger under his magatama cord, finding the spot where he knows Rairi's mark rests. He concentrates on the image, concentrates on the concept of sharing it—and Rairi starts a little bit, a blush dusting their cheeks. They turn to stare at Kaigaku, their mouth slightly open, stunned and flustered by what he's just done, and he just gives them a little smirk.

"Your order's ready, Rairi-senpai," he says, and they snap back to attention, accepting the food, trying to play it off like nothing's happened—but Kaigaku's more than aware of the color on their face, on how just the short moment of seeing themself through his eyes has gotten to them.

Of course, Rairi never goes down without a fight. It's not long before the first flash of shared vision hits him: a crystal-clear image of Kaigaku plucking a peach from a tree, his expression almost peaceful. The experience is startling enough as it is, but there's the faint impressions of Rairi's feelings overtop of it, and Kaigaku drops the fruit straight into the grass whenever he realizes that they were thinking that he looks handsome whenever he smiles.

The fact that Rairi's returned the gesture just means that it's just polite to reciprocate, so then it turns into a sort of competition to see who can catch the other off guard the most. Rairi humming as they do the laundry is met with Kaigaku looking bleary and dazed (and cute, Rairi's commentary provides) in the early morning before breakfast is met with Rairi heading towards the bath in the evening while untwisting their braid is met with one beyond unfair moment of Kaigaku practicing his stances with Sensei, worked up into a sweat, and Rairi's focus lingers on Kaigaku's open kimono and the exposed shape of his collarbone and the growing pecs underneath long enough that Kaigaku drops his bokken right then and there.

Sensei realizes what's going on and gives them both a whack for their troubles and express orders to never do that again during training or else they'll see just how he earned the title of Roaring Hashira. And while it does mean that Kaigaku doesn't have to worry about the threat of any immediate distractions, the fact that Rairi was straight up checking him out just kind of decimates anything he has that's even remotely close to focus for the day. Does this count as flirting? It sure seems like it.

Getting scolded by Sensei means that they both tone things down a bit—at least during practice. Outside of that is still fair game, and Kaigaku gets a little bit bolder with what he's sharing: the moment whenever his eyes follow the curve of their neck, his general appreciation for their face when they laugh, how much he admires and enjoys the view whenever Rairi's expression sharpens into razor focus during a sparring match. Rairi will blush and bumble a bit, but the pleased expression they get shows that they're more than happy to know how Kaigaku sees them.

Kaigaku's also not disappointed in the way Rairi sees him, though they're just a bit sneakier with their timing. Kaigaku enjoys sending over a snapshot in the moment, but Rairi's good at capturing the memories to hoard away for later. Kaigaku's tending to the orchard when he gets hit by the first one, Rairi eyeing his pulse point earlier that morning just underneath his magatama pendant. Another evening, he's soaking in the bath whenever it's another image of Rairi appreciating his muscle through the kimono he just might have left open a little bit more than usual to see how they'd react. That moment was bad enough as it is, but one evening whenever he's settling into his futon for some sleep there's an all too vivid image of Rairi watching peach juice shimmer on his lips and thinking about kissing him that drags Kaigaku right out of bed and to the room next to his, pulling open the door.

"If you wanted to kiss me," he says, just managing to keep his voice even, "all you had to do was ask."

Rairi's already tucked under the blankets, lying on their side, and they roll to sit up. There's just enough light in the hall leaking in around Kaigaku's shadow to catch the victorious little smirk on their lips. "I wasn't aware that was something that was okay with your rules, Kaigaku."

Kaigaku groans, because he did make the rules—but there's no sense in pretending that their soulmate bond isn't romantic. Rairi only sits there, waiting for him to make a call, looking beyond smug at the circumstances. "Fuck the rules," he says, stepping into the room and crossing over to the side of the futon. They've been skirting around them for ages at this point. He sits at Rairi's side, looks them dead in the eyes, half impressed that they haven't already said some smart remark or another by the time he gets there. "I decided. No more of that. So are you going to ask to kiss me, or do I have to do it myself?" Because sharing Rairi's memories means that Kaigaku understands the importance of consent, especially to them, and he knows that sharing the fantasy across their soulmate bond is close but not quite there.

"I want to kiss you," Rairi says, and Kaigaku's gotten good enough to catch the apprehension on their face to not just dive in right there. "I want to do a lot of things with you, Kaigaku. I want to hug you. I want to hold your hand. I want to make sure you know you can do these things to me, and I want to know if these things are okay for me to do to you."

Kaigaku still thinks about the damn absolute electric feeling that resonates between them whenever they have skin contact, thinks of that absolute warmth filling up his chest. "Yes," he says, reaching out his hand to take one of theirs, the fingers still warm from being tucked under the blankets. "Yes to all of that."

"Okay. Okay, good." Did they expect him not to agree to that? Did they expect him not to want that with every image he's sent to them these past month? Those words are an agreement, and Kaigaku's free hand brushes over Rairi's cheek to slip behind their head to pull their mouth to his—and then they blurt, "If we're doing this, I want to be your partner."

I want to be your partner. As in Kaigaku's, his, with him being theirs, and that privilege still feels like a blessing he doesn't deserve—but he wants it, and Rairi was right, this is their decision to make, so he can't fight them on that front without it being an utter waste of time.

Kaigaku settles for lifting up Rairi's knuckles for a quick kiss, their skin soft under his lips, and he hears their breath hitch. "Fair enough. If you don't mind that I don't have anything I can offer besides myself, Rairi, I'll gladly be your husband."

"Hus—eh? Eh?" Rairi's voice jumps up in pitch, and Kaigaku doesn't think he's ever heard them stutter so much. Their free hand presses into their face, their next words muffled. "Right, right, Taishō Era, 1920s, all that jazz—"

"Are things really that different?" Kaigaku asks. He picked up a lot of information from their deep drive through the marks, but there are still plenty of missing pieces that he hasn't had the opportunity to ask about.

"I mean, yes?" Rairi's looking anywhere but him, and Kaigaku tucks that image away to share later on, a reminder of how embarrassed they can look. "People our age don't date thinking about marriage; hell, I know people way older than me that aren't married yet! You date for a while, and some couples just stay like that without ever getting hitched, and just—" They suck in a breath, steadying themself. "This isn't because there's something wrong with you, Kaigaku. I just never saw myself getting engaged until, like, at least ten years from now, never mind getting married, and I wasn't expecting in the slightest, but…" Rairi pulls Kaigaku's hand to them, pressing a kiss along his knuckles in return. "You're my soulmate, Kaigaku. And I can't offer anything besides myself, either, but, if you're okay with that and you don't mind waiting until we've been together a while first, I'll marry you."

"Whatever you're comfortable with. So long as we're together." Hell, Kaigaku would even be okay with not getting married—but that Rairi's willing to stick with him, has chosen to stick with him feels like a complete victory. He thinks to the two other names on Rairi's skin. "About the others—"

This time, it's Rairi's hand pressed against Kaigaku's cheek, the gentle gesture stilling him. "We can figure that out once we know what our bonds are like," Rairi says, that stunning little smile of theirs easily chasing the topic of conversation away. "Right now would be a super romantic time to kiss, you know."

"Well," Kaigaku breathes as Rairi moves towards him, "I wouldn't want to disappoint my new betrothed."

Rairi chuckles, close enough for their breath to dance over Kaigaku's skin. "I wouldn't recommend it."

Their lips connect, though they don't quite make a perfect landing. Kaigaku adjusts quick enough before Rairi can get out some smart remark or another. Even when it's chaste, it's just as electric as everything else. Kaigaku's sure it can't get much better than this, but then Rairi's fingers worm their way under the back of Kaigaku's choker, the sensation from their perspective doubling over Kaigaku's, and he openly gasps, overwhelmed all over again. Rairi giggles a little bit, a grin visible on their lips—and Kaigaku presses his palm over the back of their neck, pulling them back into a fresh kiss and returning the favor. Rairi's the one that gasps next, and then their souls are resonating with each other in a moment that has no damn business feeling that much like heaven for how fucking simple it is.

"Wow," Rairi murmurs whenever they both at last pull back, foreheads pressed against each other. Rairi's fingers curl against Kaigaku's scalp, a gentle scratch of their nails.

"Yeah, wow," Kaigaku agrees, because that about sums it up. The idea of anything being able to feel better than that seems a little impossible—but it's beyond obvious that they're both inexperienced at this sort of thing, so then, with practice maybe…? Gods, he gets to be with Rairi for the rest of his life and figure it out. So long as he gets that right, Kaigaku will gladly put in the work that Sensei mentioned is necessary, no questions asked. "So…do that more often?"

"Yeah, for sure." Rairi's next laugh is a giggle, and they throw their arms around Kaigaku's shoulders in a hug, almost tipping him over as he hooks his arms around their waist, enjoying the warmth of the moment. "This, too. All of this. All of you." Even without touching the marks, Kaigaku can still feel Rairi's happiness as clearly as his own. "We should…maybe tell Sensei what we decided? He's…pretty much our guardian, right?"

That's true enough. Kaigaku's not used to having anyone else looking out for him, but Sensei is teaching them. It's the closest he can get to asking Rairi's family for permission, considering the whole displaced from time thing. Sensei, who knows about soulmates, will give them his blessing, so long as they still focus on their training. Right?

"We can do that tomorrow," Kaigaku says, deciding that there's very little that's going to convince him to let go of Rairi right now. At the very least he's not going to risk disturbing Sensei's rest over something that can wait a little while. "Um, about…going to sleep…"

"You want…to sleep beside me?" Kaigaku nods, glad that Rairi's still close enough to not see his blushing over something so simple. The two of them are partners now, so it's not that odd of a request—so why is he so flustered about it? "I'd be okay with that, just…only cuddling, okay?"

"That's more than enough."

It's the best night of sleep Kaigaku has had in years.

[Author's Notes]

And now, making up for the last update of night streets, take some soulmate fluff. As you may have guessed by my fixation on reincarnation plotlines, soulmates are easily one of my favorite tropes, so you know I had to mix that into one of these AUs.

Thanks to manchua, Adelajda000, Barbara Fang, AwePol, ethanwood818, and anyone else who dropped off a fav or follow on the walk steady series while fanfic's email notifs were a disaster. You're all incredible.

A few small notes on the mechanics:

- Rairi's other marks are Zenitsu (on the finger) and Shimizu (on the wrist, but not written in kanji). Neither of these two can see marks, but Zenitsu can kind of hear the resonance between souls.

- Likewise, Rairi's name on Kaigaku is also written in roman characters.

- Because soulmates are magic, Kaigaku didn't have any marks until Rairi got isekai'd, which is why he had no idea about the name on his neck.

- Yes, Kuwajima has a soulmate. No, I'm not telling (mostly because I'm still settling all my Sensei headcanons). Go nuts.

I would obs love to write more in this AU one day to work with the others, but this seemed like a good stopping point, so we can just leave it here.

On the note of what's next, I have a giant pile of half-written stuff I've been letting incubate while feeling inspired hardcore to work on my Moriarty the Patriot fic, so I don't have concrete plans on what to finish next. I do, however, have a special surprise waiting for the fanfic anniversary in January, so keep an eye out. (Hint: the best way to see it is to follow me in general or follow the series on AO3.) Please look forward to it!

-Avi

[11.25.2023]