He hadn't been expecting the blast to be that close.

The sharp staccato crack of explosion after explosion made Izuku's ears ache, leaving behind a faint buzzing. It took all of the experience Izuku had gained through drilling in class, fighting villains, and training with All Might to dodge in time. The familiar heat made it clear he'd barely escaped that hit head-on. Izuku could feel the hairs on his arms singe from the proximity of the blast Katsuki had set off.

Izuku made a face, trying not to gag as the acrid scent of sulfur and smoke invaded his lungs, coated his tongue. Why did nitroglycerin have to smell like rotten eggs once it had been set off? It smelled sweet before it was ignited. Spots danced in front of his eyes, residue from another brilliant flash, the flame so hot it had been white at times. He was used to Katsuki's explosions, he had been dealing with them since he was four. But that didn't make facing them, or their after-effects, any easier.

Katsuki had been creating bigger detonations recently, giving him greater range during a skirmish. Which kind of sucked, since he was already really good at combat. Now Izuku had to focus on getting close enough to actually hit Katsuki without getting burned in the process. And that was if he was being nice.

"Kacchan, be careful!"

"Be better!"

Izuku grit his teeth, eyes narrowing at the arrogant challenge in those words. He could feel the electricity dancing over his skin, the accompanying power coursing through his veins as he increased the percentage of his Full Cowl to fifteen percent. All he needed to do was get close enough to land a blow...

He darted forward, muscles pumping as he avoided Katsuki's blasts with the smallest of adjustments, narrow misses that allowed him to weave a twisting path through the churned-up rubble and dirt. Giving Katsuki more room to maneuver and fire off blasts was only going to keep up this stalemate. He dived, hissing in a breath as his shoulder connected with debris he hadn't spotted, sending pain skittering up and down his nerves. The blast above his head was scorching, another near miss that made Izuku grin, made Katsuki curse in the background.

He was going to win this time.

He rolled and surged to his feet, leg muscles tensing and releasing as he used the momentum to propel himself up, leaving the ground below him, crossing the distance between him and Katsuki with stunning speed.

Katsuki looked up, released another explosion from his hands in an attempt to ward off Izuku. The blaze of radiant light dazed him, leaving him blinking rapidly in an attempt to clear his vision. Izuku coughed, lungs straining for oxygen.

It was instinct at this point to reach for one of the kicks in his arsenal. Speed and power combined as he snapped his leg around to generate an intense gust of wind, blowing Katsuki's attack away and giving him the room to follow up with his own attack.

He plummeted to the ground, eager to trade blows with his opponent now that he'd closed the distance between them. The earth splintered as his feet connected, a rolling roar that vibrated through Izuku's body, mixing with the sparks of pain that chased up his legs. He could deal with aches, knew how to push past the discomfort and keep going. It barely phased him at this point, for better or for worse.

Adrenaline pushed him forward, blended with the quirk he had worked to make his own. He spun, lashing out with a kick that connected with Katsuki's torso, sending the blond skidding back several feet.

The snarl ripped from Katsuki's throat was almost as powerful as the explosions he fired in quick bursts of light and roars of sound, closing the distance Izuku had created in seconds. Izuku reacted without thinking, throwing his weight behind the punch, rotating his shoulder as he followed through. Fist hit palm as Katsuki attacked, catching Izuku's punch with his own attack, fire and electricity combining.

Contingency plans flashed through Izuku's mind as they traded blows, discarded and considered in milliseconds. Part of the challenge fighting Katsuki was that he was gifted in combat. It was like a game of chess, each blow, each block a smaller game won or lost. It was a challenge that allowed Izuku to test himself as they danced, possible scenarios spinning through his brain, played out before they were ever put into action.

Katsuki favored open-palmed attacks that allowed him to use his explosions to their full effect. Izuku had learned over time to utilize kicks, but punches still remained a vital part of his fighting style whenever he was sparring with Katsuki. Izuku devised how to apply his quirk in new ways, pushed himself to new heights.

Izuku had studied quirks for most of his life, and Katsuki's quirk in particular. Part of the reason that Izuku had a hard time adjusting to One for All and the sheer power now at his disposal, was that his body didn't have any secondary quirks in a way, to support him, to take some of that strain. Katsuki on the other hand, did. Because he had been born with his quirk, his arms were built to handle the recoil better, his body could withstand nitroglycerin alongside other bodily fluids. Katsuki's bones, his muscles, everything was built to withstand the power he produced. It was probably why he gained muscle easier, too. Katsuki had few weaknesses and worked hard to make sure that no one saw any. Izuku had no such luck, and had a plethora of weaknesses due to the fact that his own body could barely handle his quirk.

But Katsuki did have one weakness Izuku could exploit if he moved just right. His shoulder joints protected him against the ricochet of his own power, but at another angle they were as weak as anyone else's, maybe weaker in some ways. All Izuku needed was a chance.

He jumped back, widening the distance between the two of them. He rotated both of his arms in a cyclical fashion, keeping his movements small, contained, building up velocity, generating a wind current the faster he moved. The force of it ruffled his hair, made his eyes smart as the gusts grew stronger, but he didn't look away, didn't take his eyes off of Katsuki for even a moment to blink. He couldn't afford to.

Katsuki darted forward, intent on stopping Izuku before he could attack...and played right into Izuku's hands. He released the wind current he had built up with a sharp movement, discharging it in such a way that it rushed directly into Katsuki's face, made his eyes water.

"Shit!"

Izuku closed the remaining space between them, shifting to stand behind Katsuki before the blond could blink. One hand grasped Katsuki's wrist, the other pressed against his friend's shoulder and Izuku applied pressure, forcing the joint the wrong way. One dislocation and Izuku was hoping the fight would be over.

Katsuki gasped, surprise and pain weaving together, the noise echoing in Izuku's mind. He hesitated for a moment, heart slamming against his ribs, grip loosening a little, almost as though remembering that this was Katsuki, not an enemy he had to defeat at any cost.

It was all the opening Katsuki needed.

He released an explosion as he wrenched away, sending a scorching heat and pain shooting up Izuku's arm. He released Katsuki with bitten-of cry, instinct driving him to cradle the injured appendage close to his body.

Katsuki fired off multiple rapid explosions, using the torque to spin him to face Izuku. Katsuki discharged another explosion as his palm connected with Izuku's chest, sending him flying through the air, pain radiating through his ribs.

Izuku slammed into the ground hard, breath leaving him in a harsh exhale, lungs struggling to draw another one. He started to push up, trying to push past his body's need for air, knowing Katsuki was coming.

And then Katsuki was there, hand on Izuku's throat, one booted foot pinning Izuku's dominant arm to the ground as he knelt over him.

"I win."

"Yeah," Izuku rasped, coughing. "You win...Damn it."

Katsuki smirked and stood to his full height, offered Izuku a hand and pulled him to his feet. "Nice try though, nerd."

"Thanks." Izuku smiled.

"I'm going to remember that trick for next time."

"I'll think of something else then."

"You can fucking try," Katsuki grinned.

"I am never going against either one of you in a fight again. Fuck that!"

Izuku turned to see Ashido and Kaminari leaning against the fence that separated the field from the rest of school.

"Ashido-chan, you can create a corrosive liquid. Compared to that…" Izuku cocked his head.

"I don't care. You two are like forces of nature, and I like living." Ashido shook her head, glancing to the blond at her side. "Kaminari, back me up."

"What she said." Kaminari nodded quickly, looking between Izuku and Katsuki with wide eyes. "At least give me time to catch up or something."

"Fucking wimps." Katsuki rolled his eyes. "Whatever, at least Deku gives me a challenge now and again."

"Be nice, Kacchan," Izuku smiled, shaking his head.

Adrenaline drained from his limbs slowly, leaving him to feel the aftermath from their fight. His whole body was a constant ache from the blows traded between the two of them, and Izuku had been injured often enough over the past year to know that he'd be covered in bruises given a little time. He pressed on the knuckles of his right hand, wincing at the jelly-like consistency. He had a feeling he'd broken the bones at the joint again. He had to work on that.

He glanced up in time to see Katsuki rotating the shoulder he'd attempted to dislocate and bit his lip. Izuku was sure that he hadn't dislocated it, but he had probably bruised it or something given the pressure he had been putting on the joint. "Sorry."

"I'm fine." Katsuki rolled his eyes. "Would have been pissed if you'd dislocated it though."

"I doubt Recovery Girl would have been glad to see us," Izuku smiled.

"What did you two want anyway?" Katsuki scowled at Ashido and Kaminari, folding his arms across his chest.

"Kirishima said you were helping him with math earlier, and we were hoping you could help us?" Kaminari asked, shoving his hands in his pockets. "I can't afford to fail the next test."

"I came for the show," Ashido grinned, running a hand through her crazy pink hair. "Next time tell us you're sparring Midoriya. I'll sell tickets."

"Eat shit," Katsuki deadpanned before turning back towards the school. "If you want me to teach you losers, let's go."

"Yes! Alright, make me a math genius!" Kaminari cheered, crossing the distance to sling an arm over Katsuki's shoulders.

Katsuki shoved him off, producing a laugh from Ashido as she followed, smirking at Katsuki when he turned to glare at her, as if she knew something he didn't.

Izuku smiled, watching the three of them retreat. He should probably head back to the dorms soon. He had wanted to get some studying in before their upcoming exam, and there had been a chapter they would be going over next week in their Quirk Theories class that had looked fascinating. He made a metal note to ask Iida if he'd had a chance to go over the notes for their history class too, Iida might have caught something Izuku hadn't.

For now, though, he wanted to practice a few more kicks that he had been hoping to add into his style. They still didn't flow right when he tried to use them in a fight, and his sparring match with Katsuki hadn't been informative enough for Izuku's analysis. Maybe all he was missing was repetition and muscle memory?

He was glad that Katsuki had agreed to spar with him, it had given him a chance to try several new moves he had been mulling over. Izuku enjoyed sparring with Katsuki more than his other classmates, though they all brought something unique to a fight. No one challenged him the way Katsuki did though, no one made Izuku think as quickly during combat as Katsuki did. When they had been paired up on occasion since the new school year had started, they worked together, smoothing out kinks and stumbling blocks leftover from the years when they hadn't been communicating properly.

Izuku was grateful that those times were behind the two of them. Their friendship had grown since that night after the licensing exam, when Katsuki had found out about One for All and had admitted how he thought Izuku had been looking down on him. The fact that they had communicated through combat now made perfect sense, though at the time he had wondered why they had to fight to get anywhere with each other. Katsuki wasn't the best with words, but he could express himself easier with actions. Keeping that in mind had helped rebuild their friendship since then, and it had almost felt like Katsuki was trying in his own way too.

Izuku still fought with Katsuki, but it felt more even now, like they were actually equals in Katsuki's eyes. Or at least, close enough.

"Oiy, Deku!"

Izuku's head snapped over to where Katsuki stood, arms still folded over his chest. Sweat traced the muscles of his arms, his shirt sticking to his chest in a way that left little to the imagination. Dirt from the fight was smudged on his cheekbone, streaked through the ash blond of his hair. Another bead of sweat traced a path down the cords of his neck before being absorbed by his t-shirt, and Izuku's eyes followed. He swallowed against a dry throat, forcing his eyes away. Ashido and Kaminari had paused a few steps in front of him, like they had realized Katsuki wasn't walking back with them anymore and had looked back to see what was keeping him.

"You're going to lose track of time if you stay out here, and I'm not getting in trouble with Aizawa-senpai for coming to get your ass. Let's go!"

Apparently, it was Izuku that was keeping him. His traitorous heart flipped in his chest.

"Coming!"

OoOoO

Izuku stared down at his math notes, his mind unable to focus on the school work before him, despite his desire to apply himself and ensure that he received a high grade on his upcoming test. He had also wanted to check his English textbook and make sure he would be prepared for any quizzes that might come up in class tomorrow.

That had been the plan anyway. Instead he was sitting here daydreaming about his best friend.

He couldn't pinpoint exactly how long he'd had a crush on Katsuki. They had known each other their whole lives, had been friends before society had labeled Izuku as useless and Katsuki as a burgeoning hero. Katsuki had been a constant, even during middle school when their relationship had been at its most strained. He'd still been there though, had always been someone Izuku had considered his friend.

But if Katsuki had made his heart skip a beat then, it hadn't been in the way it did now.

He supposed it had been sometime during their first year at U.A. that he'd realized he had a crush on his childhood friend. U.A. had helped him come out of his shell, had given him a confidence he had lacked the rest of his life. For the first time in quite some time he'd had friends he could rely on, friends who wanted to spend time with him. He'd felt normal, and that had been refreshing, almost overwhelming at times.

But would they have spent any time with him had they known he'd grown up quirkless? That the only reason he was even their classmate was because All Might had stepped in and made his dreams come true? Izuku wanted to believe they would, but he couldn't be sure, not with the way society labeled those who were unlucky enough to be born quirkless. On the other hand, Katsuki had known Izuku when he was quirkless, had still spent time with him for several years afterwards.

U.A. had given them both the ability to stretch and grow, to start to come into their own. They had still been together, but now they had the assuredness to challenge each other, to evolve together.

Would Izuku have realized his feelings without that chance? He didn't know for sure but he somehow doubted it. In gaining friends outside of Katsuki he had been given the opportunity to step back and decide what he wanted in a relationship, in a partner. Not that he thought he had an actual chance with Katsuki.

Izuku sighed, pushing away from his desk and the books that he was most certainly not focusing on. It wasn't midnight quite yet, but he wasn't going to be able to retain any of the information he was reading. He didn't think he'd even turned a page in several minutes, too distracted by his own thoughts. He flicked off the lamp, plunging the room into darkness and crossed the space to his bed.

He flopped down, staring up at the ceiling unseeingly, memories of his first year at U.A. cascading through his mind.

At first, he had thought that he'd liked Ochako. He probably had, she'd been nice to him from the beginning, had been the first person he could call a friend outside of Katsuki in a long time. She was pretty, she talked to him like he was normal, like his opinion not only mattered but had a real weight, and they had had almost an instant connection. But as the months had passed those feelings had faded into something softer, something more stable. He could count on Ochako to be there for him through thick and thin, but there was no desire to take their relationship any farther. She was his closest friend save for Katsuki. He cared for her, deeply, but it wasn't the same.

Katsuki made butterflies come to life in his stomach, made his heart skip a beat whenever he flashed even a hint of that cocky smile. Even something simple like helping Izuku to his feet earlier had made Izuku's skin sing with awareness.

Izuku had always seen Katsuki's faults, he had just never lost sight of the positive in the other young man. But he also knew that there was more. He didn't have a crush on Katsuki because Katsuki had always been there. Stepping away, gaining his own group of friends separate from Katsuki had simply given him the chance to look at his feelings with a different lens. There was this magnetic pull that kept Izuku ensnared, that tugged him back if he ever strayed too far from Katsuki, like their lives were entwined on a level beyond what Izuku could logically explain. Which was romantic and silly and he knew that.

Katsuki made Izuku want to be better, not just as a hero, but as a person, and that was enough. It would have to be enough. He knew that it wouldn't happen, would never jeopardize the friendship he had regained with Katsuki for his silly crush.

And if Izuku daydreamed about kissing him, that was his problem.