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Even Fire Suffocates Without Oxygen

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“Fucking take it Deku!”

Izuku jumped a mile at the harsh snap, looking up from his notes and realising Kacchan was handing back the forms Mr. Aizawa had just passed out.

“S-sorry Kacchan!” he stammered, grabbing the forms and taking one before passing it over his own shoulder to Mineta.

“Fucking shit-faced nerd,” was the growl he got in response.

“Hey!” Izuku yelped, cheeks puffing out a little in indignation.

The chair in front of him was abruptly swivelled around, sparks crackling in Kacchan’s palm ominously. “Huh?!”

“Oi dude, calm down!” “Bakugou-kun, cease this behaviour at onc-”

“Break it up.” Mr. Aizawa’s voice hadn’t changed from its usual bored drawl but it was enough to quell all noise in the room. His gaze then flicked to Kacchan. “Don’t push it Bakugou.”

Kacchan tsk-ed under his breath but finally turned back to face the front. Not a single word came out of him until their next class and even then it was only because Kirishima had asked him what his whole blow-up had been about. He’d snapped something about it being none of their business and made a point of knocking Izuku’s shoulder as he strode out to lunch. That had drawn several angry protests but Izuku had been more confused than anything because this looked like middle-school Kacchan and that version of his “friend” had dissipated with the whole sludge villain incident.

A day turned into a week, which then turned into two weeks, and Kacchan still wasn’t letting up. He’d yell at everyone in the class and was more intense during practical training - something he really didn’t need to be - but it was those pointed attacks on Izuku that had the teenager becoming increasingly concerned. He hadn’t done anything lately to set Kacchan off so why the sudden change? Why was he once again the punching bag? Or rather, attempted punching bag because now he could fight back.

“Midoriya.” His thoughts were chased away by Mr. Aizawa’s voice, the teacher having them review their last practical assignment. “Whose strategy was least suited to the scenario you were presented with?”

Izuku gulped, ice pouring into his veins because… “I, I mean-...that is to say, it-...Well, there are a lot of-”


“Y-yes! I, um...I think...Kacchan, sir. His-”

“The fuck?!”

Izuku leapt back as a hand slammed down on his desk. He barely had time to shield his eyes before said desk exploded. There were a couple of startled screams from around the room but Izuku couldn’t risk focusing on them, not when Kacchan was standing over him and was already gearing up for a second attack. “Wait, Kacchan! I-”


For one moment it looked like Kacchan was going to go over Mr. Aizawa and attack anyway. Izuku wasn’t actually sure he wouldn’t have had his quirk not been erased. Kacchan growled when he realised he was unable to activate his powers, whirling around only to have a hand grip his collar roughly.

“Another display like that and you can start looking into other schools. You’re not a villain; don’t act like one.” Mr. Aizawa then released Kacchan, unblinking. “House arrest until I say otherwise.”

There was a long, tense moment before Kacchan snatched up his belongings, stomping out of the room. A string of curse words followed him and Izuku was left with that same old question: just what was going on?




“That was bad man, even for Bakugou!” Denki was saying, Izuku biting back a grimace because for him it once would have been considered normal.

“Right?” Kirishima agreed, glancing at Izuku. “He’s not...You guys grew up together, didn’t you? That was strange, yeah?”

“It was strange,” he conceded, eyes on the ground as they all trudged back to the dorms, classes finished for the day. “I mean, Kacchan’s always been explosive but...I thought, well, since starting at UA he’s do I? Not less Kacchan but less, explosive? No, I already said that. What I mean is he-”

“I think we have a bigger problem than that,” Asui cut in, pointing ahead of them.

The sight before them had Izuku’s breath catching in his throat because no, he’d never seen this. The training ground next to the student housing was completely and utterly torn apart. It was like an entire minefield had been detonated...and then consumed by a roaring wildfire. Some areas still smoldered, residual heat from Kacchan’s explosions keeping them alight.

“Oi, oi, isn’t this a bit much?” Sero asked in alarm.

“I-...” Izuku then let out a gasp. “Kacchan.”

He’d finally spotted him, on his knees in the centre of all the destruction. His palms were still igniting sporadically but it was the shaking of his shoulders that had Izuku rendered speechless. Crying. Kacchan was crying. Bakugou Katsuki, the strongest person he knew other than All Might, was openly crying.

“Well, that definitely makes it time to leave,” Ashido stated, taking quick steps in the opposite direction. “I’m not going to stick around to find out what Bakugou’s gonna do if he catches us spying on him crying.”

“A fine plan, mon amis,” Aoyama whispered, also backing away, Izuku not surprised when the majority of the class did the same. He didn’t blame them.

“Midoriya-kun?” Iida asked, voice pitched low for once. “Should we approach Bakugou-kun?”

Uraraka seemed to be of the same mind but Deku shook his head. “No. Look at the training field. Kacchan’s already volatile enough. I…,” he started to move forward. “He won’t go any easier on me-” Go harder would be more accurate, “-but I can take it.” Or rather, I’m used to it.

A hand settled on his shoulder, pushing him back. “No. I’ll handle him. He’s my friend.”


The red head flashed him a thumbs up. “Blasty’s yet to actually blast me so, you know, gotta build that manly respect.”

Izuku blinked in surprise before his face split into a grin. “Okay! Thanks Kirishima, and good luck!”

Kirishima winced slightly. “Thanks man, I’m gonna need it,” he said, eyeing up the devastation that lay between him and Kacchan.

Izuku gave him a tiny nudge. “You can do it. You’ve already rescued him once before, right?”

Kirishima was momentarily stunned before giving him a blinding smile. “Yeah, I did! Thanks Midoriya! I’ve got this! I’ve got this!”




Kirishima did, to some extent, “have it” because he was able to get Kacchan up and inside without being blown to pieces. Everyone had acted as natural as possible when they’d come indoors and Izuku was never quite able to determine if they’d fooled Kacchan or not. Either way, it was never brought up again.

But that also didn’t mean it stopped.

Another six days and Kacchan was still lashing out - less in class but more everywhere else. Izuku had been pinned against the wall twice in one week, something that hadn’t happened once since coming to UA. Kacchan had attempted to blow up his newest hero notebook, only unsuccessful because Tokoyami had snatched it away with dark shadow just in time. Iida had been scolding and Kirishima consoling but when it came to sparring matches that week and he was blown across the room for the fifth time, Izuku finally understood.

Something was horribly wrong. And this was the only way Kacchan could deal with it.

Clambering back to his feet, Izuku held out a hand when Mr. Aizawa came to stop them. “Sir, please, let him come.” Izuku set his shoulders, resolute. “Right now, I’m the only one who can accept Kacchan’s emotions.”

His teacher eyed him up for a long time before nodding, waving a hand as if to give his permission. Izuku nodded in thanks before marching back towards where Kacchan was waiting. He knew what he had to do now.

Another blast came his way, Izuku deflecting it with the shockwaves caused by discharging One for All. Kacchan attacked again, Izuku returning in kind. And so the cycle repeated, over and over, Izuku slowly gaining ground. He wouldn’t attack but he’d take every ounce of Kacchan’s anger. He wouldn’t fight, not like that, but he’d take each metaphorical punch.

“Fucking fight me Deku!”

It was frustrated and enraged was also shaking underneath. The distance between them was closing, Kacchan sending more and more blasts his way. ‘Desperate’ was the word Izuku would use; such an odd word to associate with Kacchan.

One last almighty explosion rocked the hall but through the smoke Izuku had seen it: Kacchan dropping to his knees once more. Crossing that last metre in a half-run, Izuku threw himself down in front of his friend, heart skipping a beat when he saw the tremors and ever so familiar appearance of Kacchan’s left arm. He’d shattered the bones inside, too many explosions, too much force.


The right hook to his cheek nearly knocked him over, head pounding. He managed to remain upright though, smiling at Kacchan sadly. Kacchan scowled and swung at him again but his fist only ended up thudding against his shoulder limply this time.

“You fucking nerd.”

Izuku’s eyes sunk shut at how choked up that sentence was. He didn’t know what to say, chewing on his bottom lip awkwardly but - shockingly - it was Kacchan who spoke first.

“ mother…” The hand on Izuku’s shoulder started to burn but he barely noticed. “She...the fucking shit doctor’s, I-...fucking terminal cancer. Three to six months or...some shit like that.”

Izuku’s stomach dropped as Kacchan drew a line across his neck; throat cancer. Aunt Mitsuki, she…

“It’s not fucking fair!” Kacchan screamed, fists pounding into the ground. “She fucking always said it would be me first but...I…” Hands scrubbed at his eyes messily. “She doesn’t even fucking smoke! How can-”

It was Izuku’s turn to lash out, the unexpected punch sending Kacchan reeling. Izuku caught him before he fell but it was more out of anger than concern. “Yo-you idiot!” he cried. “Why didn’t you say? Why did you try to hide it idiot!

He then flung his arms around Kacchan, shoulders shaking with repressed sobs even as Kacchan bit back tears. His muscles were tensed though, like he was about to be pushed away and that wasn’t okay.

“I’m not feeling sorry for you!” he hiccoughed; he was, but he knew better than to say so. “I’m just a crybaby!”

Kacchan’s arms dropped back to his side, not crying but so, so close. Izuku could only hug him with everything he had because he knew this would probably be the one time he was allowed to. Once this moment was gone, it wouldn’t come again. In a painful way, it all made sense, why Kacchan had turned on him again. Because he was hurting and had to get that hurt out somehow, even if making others hurt more than him was the wrong way to deal. But also because Izuku was the only one who knew Mitsuki. He was the only one who could even hope to understand, who knew exactly what Kacchan was losing. Not just his mother, but the person his mother, Bakugou Mitsuki, was.

And just like that a sob escaped Izuku, Kacchan snarling against his shoulder. “I told you, I’m just a crybaby!” Izuku insisted, clinging on tighter, wanting to draw this out.

He was allowed another minute or two before Kacchan pushed him away, rubbing his face with his good arm. He then got to his feet, turning his back to everyone.

“Oi Deku, where’s that shitty nurse you always go to?”

Izuku passed along the directions as best he could, reminding Kacchan to keep his arm pinned to his chest so as not jostle it. That got him a scowl but his advice was followed, the other teen seeing himself out. Izuku waited until Kacchan was well and truly gone before slumping to the ground, wailing loudly.

“Deku-kun!” “Midoriya-kun!”

A hand was on his shoulder, though he wasn’t sure whose it was.

“Midoriya.” Ah, that was Todoroki. “What did Bakugou say?”

Izuku didn’t even bother wiping his face; there was no point, the tears were going to keep coming anyway. He then glanced up at Mr. Aizawa because he was the easiest to face.

“Ka-...his mother’s dying.”




There was nothing that could be done, really. Despite the numerous quirks throughout the world, there still wasn’t one that was a cure for everything. For every advancement medicine made, diseases just continued to evolve, as they had for centuries. When it came down to cancer versus Recovery Girl, it wasn’t even the right kind of illness for her quirk to tackle.

Kacchan had known, known from the start. He was smart like that. He’d known there wasn’t a cure, that the cancer had been discovered too late, was too aggressive. He’d known he’d had to get ready to say goodbye, “weekends at home” being a cover for camping out in a hospital room.

But Class 1-A knew his secret now and suddenly he wasn’t allowed to go through it alone. Izuku had gone up immediately the day after finding out, his mother joining him because she’d known Mitsuki was sick but not like this. There had been tears and hugs and Kacchan had burst in halfway through, demanding to know why Deku was there but then it became habit. Every day a rotating handful of students from their class would take the trek to the hospital; sometimes Kacchan joined them, sometimes he didn’t. They brought jokes and stories and flowers and gifts.

Mitsuki had grabbed Izuku’s arm one day as he’d gone to leave; “Thank you. I know this wasn’t all you,” she’d said with a roll of her eyes when he’d gone to object. “And I know Katsuki’s put you through too much but, thank you. I’m happy I got to see him with proper friends at least once.”

Izuku had sobbed into his pillow for hours that night.

At the Principal’s suggestion after hearing the situation, Mr. Aizawa and Cementoss had made an area purely for Kacchan to expel his anger. There was now a training field full of concrete slabs that Kacchan could explode at will. Some days it remained perfectly intact, other days the concrete was reduced to nothing but dust.

Then came the day, Mr. Aizawa pushing open the door during Present Mic’s English class. “Bakugou, it’s time.”

Kacchan didn’t betray anything as he got to his feet, collecting his book and making for the door. “You coming, hair for brains?” he growled.

Kirishima’s jaw dropped before scrambling to his feet, not even waiting to see if he had permission or not. He was at Kacchan’s side in a second, bumping their shoulders as they reached the doorway. Kacchan then paused, so long the whole room became filled with a tense, awkward silence.

“Oi Deku, what are you fucking waiting for?!”

No one moved. No one even breathed.

Izuku was sure he’d misheard but one look at Kacchan’s face told him no, he hadn’t. He stammered out a “y-yes!!” before basically tripping and stumbling his entire way across the room. Kacchan looked ready to murder him at that but didn’t actively try to blow him up so Izuku counted it as a small victory. It didn’t matter that Kacchan dumped them outside the second they arrived at the hospital, what mattered was that they were still there when Kacchan came out several hours later, absolutely wrecked.

“Come on dude,” Kirishima said softly, taking Kacchan by the shoulders and pushing him to the back gardens, hardening his arms. “Take it out on me.”

And Kacchan did, Kirishima blocking his attacks while Izuku kept the shockwaves contained. It must have been cathartic in some way because when Masaru found them, eyes red and face drawn, Kacchan went with him willingly. Izuku was going to suggest them taking the bus to UA to give the Bakugous privacy when Kacchan’s dad offered to drive them back. They’d agreed, Kacchan allowing Masaru to keep an arm around his shoulders the whole walk to the car. The goodbye at UA was awkward, Izuku passing on condolences that got him a scoff but Masaru gave his shoulder a squeeze.

It came as no surprise that Kacchan didn’t come back to school that week. Two days to grieve, one day for the funeral - which Izuku went to, small as it was - and the weekend to spend with family. He came back with his usual flair, throwing the door open and tossing his bag under his desk. No one looked like they knew what to say, shifting in their seats until Mr. Aizawa dealt with it in what Izuku realised was the best way possible: he didn’t.

“Bakugou, Iida has your homework and Midoriya has a copy of the class notes. Try to catch up.”

Kacchan was already holding out a hand, Izuku passing the folder over and trying not to wince as Kacchan snatched it from his grip. “Geez Deku,” he huffed. “Why do you write so fucking much? It’s like I didn’t fucking miss a day.”

Izuku didn’t comment; just smiled. He knew a Kacchan thank-you when he saw one.

The rest of the day passed quickly enough and then Class 1-A was returning to their dorms, crossing the grounds as a group, talking loudly and laughing and teasing. They didn’t split up like they normally did when reaching their new “home” but rather followed Kacchan to his floor. The blond was getting ready to send them all packing, Izuku could tell, but his throat closed before he could, catching sight of his door. His door which was now covered with nineteen post-it notes, each one sharing their favourite memory of or thing about his mother. Kacchan’s hands trembled at his side, though they were spark-free for once.

“I fucking hate all of you.”

He didn’t and that’s all that really mattered in the end.