Lori
patreon
FIC - "A Shooting Star Is Just A Burning Rock"
🕑 Added 2025-08-14 16:14:05 +0000 UTCBKDKBK | Soulmates AU | canon-divergent | getting together
Written for the 2023 Summer Daze BKDKBK Reverse Big Bang ❤️ I got the opportunity to write for theboytripstar’s wonderful soulmates AU art which is so good and delightful and makes me happy to just look at! Please go see! ♥️
I’ve always wanted to write something soulmates related, so I hope I did the art justice and that you guys enjoy this little slice of dkbk sweetness.
==
A SHOOTING STAR IS JUST A BURNING ROCK
The weekend before graduation, Class 3-A gathered in the common area for one of their last shared meals.
Although he’d never admit it out loud, Katsuki would sorta-kinda miss these extras. They’d been a constant in his life for three years, and they’d grown on him. Like mold on bread.
But even more so, he was eager to complete his run as a sidekick so he could start his own agency. Most of his classmates had been working as part-time sidekicks since the beginning of third year, with several already experienced enough to go solo. It was unprecedented, but after fighting a war in their first year, 3-A was used to raising the bar.
Katsuki was one of those, obviously. As if that was ever in doubt. There was also Todoroki, who practically ran the Endeavor agency already anyway. Tokoyami, who’d been well and truly taken underwing by Hawks. Yaoyorozu had already purchased a building in Tokyo and was in the midst of planning renovations with Jirou and Kaminari.
And then there was Izuku. The nerd had spent the last two years as a sidekick at Endeavor’s agency—at least on paper. In reality, he’d been treated as a fully-fledged pro hero from the moment he awoke in the hospital after his final battle with All For One.
One of the first things Katsuki had done after the war was get Izuku’s agreement to start an agency together. It wasn’t that he needed the nerd’s help—Katsuki didn’t need anyone’s help to make his mark and rise to the top. But Izuku was a media darling, the fucking “savior of Japan” or whatever the press was calling him these days, and one of the most sought after “rookies” in the country. Whichever agency the nerd chose would become an instant household name—and an instant rival.
Unless that agency was Katsuki’s. He’d learned a lot about what a real victory looked like these last few years. Snagging All Might’s successor would be a win, and Great Explosion Murder God Dynamight always won.
Nearby, Uraraka and Asui were curled together on the sofa. Katsuki wasn’t trying to eavesdrop—the hell would he care what they talked about? But he’d left his earbuds in his dorm, and retrieving them wouldn’t be worth the effort since he was almost finished eating anyway.
“Like you said, it’s uncommon,” Uraraka was saying. “And besides, what really matters is if you both choose each other.”
Katsuki mentally sneered. This again. One by one, as each of them had turned 18, his classmates’ obsession with soulmarks had grown. Reaching adulthood meant potentially discovering your soulmate by way of a soulmark. The catch was that soulmarks only appeared through physical contact, so less than a third of all adults ever even found their person.
As far as Katsuki was concerned, it was a pointless distraction. He had goals to achieve that didn’t involve any unnecessary attachments, especially with some extra he was supposedly connected to through whatever cosmic force decided that crap. No one told him what to do.
“Deku-kun, have you started packing yet?”
Katsuki glanced up at Uraraka’s question just in time to see Izuku drop onto the sofa beside him. He was carrying a bowl of food, chopsticks balanced across the rim.
Cradling the bowl in his lap, he said, “I’ve been moving things out for a couple months now, just a little at a time.”
“Because it would take an entire moving crew to transfer your All Might shrine in one trip,” Katsuki muttered before stuffing his mouth with flakey fish. Dinner had been a group effort, and he had to admit the extras had gotten better in the kitchen over the last few years.
Color dusted Izuku’s cheeks, but he said, “It makes it easier on my mom. I didn’t want—Kacchan.”
The sudden fond smile that lit Izuku’s face caught him off guard, as did the thumb that swept across his skin, just beneath the corner of his mouth. He was so stunned by the gesture that it wasn’t until Izuku had pulled away, eyes dancing with amusement, that Katsuki thought to jerk back.
“The hell,” he said belatedly. He swiped the back of his hand over the spot that still burned from Izuku’s touch.
With a tilt of her head, Asui regarded them. Katsuki just knew she was going to say something annoying in that frank manner of hers. Usually, he liked that about her.
“Midoriya is one of the few people who can do that without getting their fingers blasted off,” she said. She had the nerve to sound thoughtful, like she wasn’t exposing his (apparently poorly guarded, what the fuck) weaknesses.
Izuku’s cheeks turned pink, and he attempted a casual shrug. “Kacchan had sauce on his face.”
“Kero.”
Katsuki took back his previous thought about missing his classmates after graduation. They could fucking rot.
“So, Bakugo, are you moving back into your parents’ house?” Uraraka asked, directing the conversation to safer ground.
“Not on your life.”
“He’s staying at the Genius Office dorms until he finds a place in the city,” Izuku said.
“Oi. Don’t go telling everyone my business.”
As if Katsuki hadn’t spoken, Izuku continued, “Since we’re also still looking for a building to establish our agency, we figured there was no point not taking advantage of sidekick dorms. Might take a while since Kacchan is picky.”
“Location is everything!” Katsuki insisted loudly.
They carried on that way for a while, with Uraraka and Asui offering their unwanted opinions on hero agency names. Then Izuku asked them what they’d been up to lately, and the girls eagerly latched back onto the topic of soulmates.
“Midoriya, has your soulmark appeared?” Asui asked.
At the question, Katsuki’s stomach clenched, the food in his mouth going stale as he stopped chewing. Even his heart seemed to slow in anticipation.
“No,” Izuku admitted, and Katsuki’s heart jumpstarted again with a shuddering thump. “I know it’s a pretty low probability, but I'm looking forward to if it happens.”
“Pfft,” Katsuki couldn’t help cutting in. “Don’t tell me you buy into that fated bullshit.”
He gave an infuriating little smile. “I think it’s nice to know there’s someone out there who was meant just for me, you know?”
“Deku-kun, that’s so romantic!” Uraraka said even as Katsuki scoffed.
The hell did Izuku need some stranger for? He had a class full of friends who had fought a war for him, who had fought with him. People he’d grown up with, who knew him, who would die for him. Was that not fucking enough?
A vague burning sensation started below his collarbone. He twitched his left shoulder but otherwise ignored it. Sometimes his various scars twinged, the sensation of pain more memory than real.
“But it doesn’t have to mean anything if you don’t want it to,” Asui added. “Ochako-chan was just saying that it’s always about choice. And it doesn’t even have to be romantic.”
Soulmarks were still a new enough phenomenon—appearing only a couple generations ago—that it wasn’t entirely understood yet. And since it wasn’t dangerous and caused nothing worse than an inconvenient tattoo that couldn’t be removed, research simply wasn’t as prioritized. In fact, a small movement had sprung up around covering rejected soulmarks with intricate ink designs.
“I hope mine is romantic though,” Uraraka said with a sigh. “If it ever even happens.”
“Whatever, losers,” Katsuki said, rising from the sofa. He ignored Izuku’s soft “Kacchan?” as he headed into the kitchen to rinse his plate and set it in the dishwasher.
When he returned to the common area, he found a spot near Kirishima, Kaminari, and Sero, who were ranking the most destructive ultimate moves on a scale of “Mineta Beads” to “United States of Smash.” It was stupid, but he could deal with the mindless fun if it meant pretending not to notice the green gaze that followed him through the room.
+++
By the time Katsuki returned to his dorm, it was well past curfew.
As he changed into his pajamas, pinpricks of pain seared the skin of his chest. He swore, rolling his shoulder and digging his fingers into the phantom pain. It had been stinging and burning all evening, more so than usual, but he wasn’t going to bother Recovery Girl about it unless it continued into the week, and even then, only if it became a real hindrance.
He headed into his bathroom and was in the middle of brushing his teeth when he finally, truly focused on his reflection. And then he dropped his toothbrush.
A name was scrawled into his chest beneath his left collarbone. It was actually still being scrawled, as the final strokes of a kanji character glimmered eerily, as if lit from within. When it finished, the soulmark settled into solid black lines.
His heart began to race, pounding through his skull, his chest, his blood.
He would recognize that kanji anywhere. Midoriya Izuku.
Fucking Deku.
With more swearing, he collected his toothbrush and then spit toothpaste foam into the sink. He couldn’t look at his reflection as he rinsed his mouth and washed his face, going through the motions in an attempt to stall the incoming tidal wave of emotional wreckage. He could feel it swelling within him, gathering speed and devastation. Izuku was his soulmate. Izuku was his soulmate. Holy fuck, Izuku was his soulmate.
Shit. When he finally forced himself to look again into the mirror, he was horrified to find his face an embarrassing shade of red. He blamed it on his outrage.
Outrage with that stupid, useless, incredible, brave Deku because that nerd had been branded into his soul since grade school, and now—
And now… it would be both literal and figurative. Not only that, but it was in such a visible location, especially given his summer hero costume, that it might as well be stamped across his forehead.
Soulmarks only appeared with physical contact. He thought back on the evening, but it didn’t take long to hone in on the right moment.
He touched his face, just beneath his mouth where Izuku’s thumb had brushed his skin.
Why would the soulmark only be appearing now, when he and Izuku had been eighteen for nearly a year already? There was no way they’d spent the entire past year without any kind of physical contact. They trained regularly. They were paired together on patrols all the time. They hung out in close company during movie nights, study sessions, shared meals. The nerd sat behind him in class!
Except the longer he stood over the sink, glaring at the elegant black lines of his soulmark, the more he realized that he and Izuku really, actually didn’t do skin-to-skin contact. The fuck?
When they trained in costume, they wore gloves, and Izuku’s costume covered him from his reinforced sneakers to his stupidly useless bunny hood thing that he refused to change. When they trained in their UA gym clothes, Izuku maintained his distance from Katsuki’s explosive hands with any combination of his various quirks.
When they hung out after classes, Katsuki was constantly and acutely aware of Izuku and the physical space he occupied. Any contact between them—shoulders brushing, knees knocking, elbows jabbing—was through the barrier of clothing. Izuku wasn’t like Katsuki’s other friends whose physical displays of affection he dodged on a daily basis.
That was kind of weird, right? To go nearly a year spending as much time as they did together and not experiencing some form of skin contact, even accidentally… Except, maybe it wasn’t accidental at all.
Shaking his head, he flicked off the bathroom light and marched over to his dresser. He dug out an old t-shirt, which he swapped for the black tank he usually slept in. He might as well get used to covering up the damn thing.
Unbidden, Asui’s earlier comment came to him. The soulmark didn’t have to mean anything if he didn’t want it to. But… did he want it to?
He didn’t like the idea of some outside force influencing his emotions, or having a hand in the way he and Izuku had always revolved around one another. He still considered the whole concept of soulmates to be a waste of time and energy, but now that he knew his was Izuku… Now that he knew Izuku was his…
He flopped onto the bed, linked hands pillowing his head. If he knew Izuku—and he did—the nerd wouldn’t let Katsuki pretend like nothing had changed. They would have to talk tomorrow. Lay out the boundaries of… whatever this was going to be. Just the idea of it set his pulse racing again. His fingers found their way to his chest, curling against the kanji now hidden beneath his shirt.
On his headboard shelf, his phone vibrated. He tensed. Reaching for his phone, he steeled himself. Sure enough, a message from Izuku lit up his Lock Screen.
Deku: Are you still up?
Deku: Kacchan?
Deku: Can we talk? About… you know.
Deku: Unless you haven’t seen it yet. Oh no. Ah! Ignore this! I’ll just find you in the morning or something.
Deku: But I don’t think I’ll be able to sleep tonight. My brain won’t stop cycling through every possible scenario of how this could go. What this will change.
Deku: I don’t want things to change.
Deku: I mean, I do, but I also don’t? I’d be okay with just… I don’t know. Can we talk anyway?
Deku: You’re probably asleep. Text me back when you see this?
Me: FFS DEKU
Deku: You’re awake! Oh no did I wake you? I didn’t mean to, but since you’re up, can we talk? Have you, uuuuuh, looked in the mirror lately?
Deku: Kacchan?
Deku: …
Deku: Kacchan.
Deku: Kacchan, come on.
Deku: …
Deku: Kacchan!
Deku: Open your door.
Katsuki had a second to think ‘ the hell?’ before a quiet knock sounded at his door. He didn’t move, entertaining the idea of simply ignoring him. He was supposed to get the rest of the night to prepare for this conversation, fucking Deku.
There was another knock, louder this time. With an exaggerated groan that he fully intended Izuku to hear, he rolled out of bed to unlock the door.
Another thing he was not prepared for was Izuku in rumpled pajama bottoms and an old t-shirt, collar gaping like he’d yanked on it. The reason for his stretched collar peeked out from behind the worn cotton—bold black lines that Katsuki had no trouble identifying as his own name. With a deep steadying breath, he stepped aside to let Izuku in.
Izuku paused beside Katsuki’s desk, shoulders hunched, hands fidgeting with the hem of his tee. Katsuki was familiar with his body language—it was how the nerd looked when he was feeling uncertain or insecure. At eighteen, Deku had fought more genuinely dangerous opponents than most heroes encountered in their entire careers, but somehow, he was still shit at hiding his emotions.
Katsuki might’ve always been consciously aware of the space (or lack thereof) between them, but at least there’d also been comfort. Familiarity. Now, the awkwardness stretched the distance to unbearable lengths.
“Did you mean what you said about…” Izuku flushed, looking embarrassed but determined. “About this being… bullshit?” He emphasized the word ‘this’ with a vague gesture at his chest.
Katsuki’s eyes narrowed. He should have spoken first. Whenever he had to contend with an uncomfortable conversation, he liked being the one to set the tone. He liked going on the offensive and forcing his opponent to respond in defense.
Except… he had no idea what to do about this. Part of him wanted to scoff and tell Izuku that their soulmarks didn’t mean anything. They’d gone eighteen years without them just fine so why should that change now?
But another part of him wanted… something he shouldn't. Something he’d buried a long time ago. Something he hadn’t dared to look at in years for fear of conjuring its ghost and all the yearning that came with it.
“Kacchan?” Izuku prompted, something small and almost hopeful conveyed through that one, simple word.
“I don’t say shit I don’t mean,” he said at last. Then, because he couldn’t stand the way Izuku seemed to draw even tighter into himself, dark lashes shielding his eyes, Katsuki added, “It’s stupid to give fate that kind of control over the choices we make. No one would ever learn from their mistakes if they can just blame it on fate.”
Izuku’s head tilted, a spark of interest lit within green irises. “That makes sense. Even if…” His fingers brushed the edges of his soulmark just visible beneath his collar. “Even if this doesn’t mean anything to you, and I do understand why, I… To be honest, I really hoped it would be you.”
Katsuki felt his breath catch as his head filled with static. Had he just…? But why? Why would Izuku hope to be soulmates with him? It made no sense.
“I’ll also understand if you don’t want me as an agency partner anymore. I-I know it might get awk—”
“The hell are you saying?” Katsuki snapped, his thoughts refocusing at the notion of starting an agency without Izuku. “You’re not messing up my plans, stupid Deku. We already laid it out—a five-year plan and a ten-year plan. If you think you can back out now, I’ll blast your fucking face off.”
Large green eyes blinked at him. Then, the idiot turned a deep scarlet even though he’d been the one to say that sentimental crap about hoping Katsuki was his soulmate.
And maybe, once, years and years ago when the cast of his shadow had possessed wild curls and freckles, Katsuki might have hoped Izuku was his as well.
He was no longer that boy, which was why his feelings for Izuku had nothing to do with soulmarks. What he felt for the nerd was the culmination of more than a decade of friendship and fall out, of resentment, of anger and rivalry and awakenings and redemption. Of Izuku being the only person who’d seen every ugly, broken part of him and chosen to remain in his life regardless. Of Katsuki having made his peace with the possibility that he might never reach Izuku, but he was okay with that so long as Izuku continued looking at him.
Shoulders slightly less tensed, Izuku rubbed the back of his neck, which was still red. “Did you, uh, want to keep this quiet? It might be a little hard with shared locker rooms and the baths and stuff, especially with where the soulmark is located, but I’m sure we could get some skin patches to cover—”
“If I cover this damn thing, it’ll be because it’s our business and no one else’s,” Katsuki said. “Not because I’m hiding anything.”
Then he did something on impulse, something he refused to think any deeper on because that way lay truths that he wasn’t yet ready to confront—Katsuki took Izuku’s hand. He startled almost violently at the contact, and his skin was clammy, evidence of his anxiety.
Katsuki didn’t mind. Gaze steady, he tugged lightly, closing the scant distance between them. Slowly, so that the other boy could pull away if he wanted, Katsuki leaned in and pressed their mouths together.
It was quick and chaste, but the kiss rocked through him like an aftershock, vibrating through the characters branded into his skin.
“Kacchan,” Izuku whispered, soft and breathless, eyes watery with awe. Katsuki was almost embarrassed for him.
And if Katsuki’s heart skipped a beat, it was only because the damn thing had broken once before getting sewn back together.
“I still don’t believe in fate,” he said. “But I don’t do anything in half measures either. Better prepare yourself, Nerd. You’re mine now.” And everyone would know it.
Maybe these soulmarks weren’t completely pointless after all.
~fin
