Work Text:
It had honestly been a coincidence when finding Izuku. Kirishima had been on his way to work, locking the door behind him, looking down to see a black mound on Katsuki's outdoor bed when Katsuki decided to 'brave the harsh and deadly wilderness' and go outside.
(The bed has never been used.)
Kirishima didn't pay any mind to the shaking, tiny lump in Katsuki's outside bed before taking a second look, seeing bright, teary green eyes look up into his soul.
BAM. Critical hit to his animal-lover heart.
Kirishima carefully kneeled down, watching the tiny lump puff up, looking just like a little soot-sprite.
BAM. Double hit! Kirishima is going to die from the cuteness.
The little kitten tried to hiss valiantly, looking fearful but melted as soon as Kirishima stroked the little puff-balls head, little purrs echoing. Kirishima cooed softly, "Awe...you're so cute..."
BANG!
The two lept a foot in the air, the little soot-sprite kitten ducking under Kirishima's legs, quaking in fear as Kirishima looked at the window beside the door. Katsuki stood there, looking quite cross-eyed from how angry he looked, slapping the glass with all his might. Katsuki was basically quaking in anger, eyes starting to go into dangerous territory from how crossed they were. His tail was whipping in anger, lips curled into a snarl.
Kirishima snickered, carefully picking up the little shaking puffball that was still hiding behind his foot. The little kitten mewled pitifully as Kirishima carefully stroked little freckled paw pads, warm fingers rubbing over slightly coarse pads. The kitten melted into his palms, curling up in his hand, so small there was still space! It was so small! Kirishima carefully unlocked the door, closing the door behind him as Katsuki turned around where he sat on the window sill, stilling when the tiny kitten looked up at him, pawing Kirishima's thumb with a soft, rattling purr. Kirishima was pretty sure when he turned; the loud thump was Katsuki banging his head against the window.
Dramatic.
When Kirishima carefully bathed the little kitten, the little thing basically doubled in fluff. Seriously. Now he hardly fit in his hand with how fuzzy he was. Thankfully when he placed the little thing that he now called Izuku, Katsuki didn't try anything. All he did was glower from the top of his cat tree.
...that Izuku was trying to climb.
Shit.
Kirishima looked away for a moment, and bam! Izuku was two levels away from Katsuki, who didn't look pleased to be sharing his throne with a little fuzzy bastard. He tried to hiss and to intimidate the little intruder, but that didn't seem to faze the little kitten, who's probably seen even scarier cats than Katsuki.
Like...alley cats. Shiver.
Izuku hopped up into Katsuki's throne, mewing at the blond cat who was basically frothing at the mouth. Izuku grunted softly as Kirishima watched amused on the couch, still wary in case Katsuki decided to shove the little thing out of the throne entirely. Izuku suddenly swung his tiny paw and smacked Katsuki right in the face when the blond cat had hissed at him. Katsuki was...stunned!
The poor thing went completely crossed-eyed, staring at the little paw batting at his nose, Izuku grumpily meowing. Izuku seemed happy with how the cat had quieted down, removing his paw, Katsuki still crossed-eyed, curling up next to the larger cat, who bristled at the small body pressing into his side.
Success! Shut the big cat up and cuddle!
Izuku purred happily, digging his body into Katsuki's surprisingly soft spiked fur, rumbling happily as Kirishima died on the couch from cackling. Meanwhile, Katsuki was having a crisis. How dare this..this PEASANT back-talk him! Him! THE KING! This...this little cretan assaulted him! His poor nose! Woe! Woe is him! He's going to die from something this mangey thing gave him! His nose is going to shrivel up and fall off!
He'll no longer be able to smell anything! Icy-hot nearly lost his nose to a cretan his owner took in called Dabi! Was he going to contract whatever the hell Icyhot had?! Oh god, he's gonna go stupid! Katsuki let out a caterwaul of anguish before his hind leg viciously kicked the little monster out of his throne, sending the kitten flying. The thing made an aborted strangled sound as it soared out, stopping for a moment mid-air before falling to its doom down below! AHAHA! Take that, little monster! Feel Katsuki's wrath! Katsuki threw his head back as he cackled, claws digging and kneading his throne cushion with glee as the intruder fell to his doom!
Kirishima watched the scene unfurl as the Izuku was ruthlessly donkey-kicked out of Katsuki's throne. However, the kitten didn't let up, managing to snatch the cloth of the underside of Katsuki's throne, a fierce look in his eyes. Kirishima immediately whipped his phone out the moment Katsuki started caterwauling like the bastard he was, the caterwauls sounding very similar to heinous cackles. Kirishima watched as the kitten climbed his way back up into Katsuki's throne, a fuzzy paw emerging from below the throne cushion, batting at the cushion, claws sinking in for leverage as little feet flailed for purchase.
Katsuki looked over, seeing the tiny paw emerge from the depths. His jaw dropped in complete shock and...horror! No..! NO! Katsuki jumped up, back arching with a hiss, watching the little kitten pull himself up onto his throne. NO!!! The little bastard looked vicious! Katsuki was going to die. Katsuki hissed, attempting to swipe at the creature invading his throne, backing up as the kitten pulled himself up onto the cushion, meowing angrily.
Katsuki had no choice...His kingdom was going to be overtaken...! His throne was going to be someone else's..! he wasn't born for fighting! His claws weren't for this type of shit! But this...! This little monster was, from the way he hissed and cried out his battle cries! The little thing left Katsuki with no choice...
ABANDON SHIP!
Katsuki ducked a pitiful swipe to the nose, scrambling back, jumping off of his throne, going to brave the dusty, windy depths below, wailing his sorrows as he fell thousands of feet to his demise!
(It was seven feet off the ground..)
Katsuki hardly managed to brave the fall, nearly falling flat on his face as he slipped and slid around on the hardwood floor, managing to find traction on the carpet, hauling ass to hide under the couch. Izuku mewled and purred as he became loaf on cushion, ruling over his new kingdom while Katsuki quivered under the couch.
Woe...! Woe is him!! His throne...
Katsuki never managed to win his precious throne back as the years went on, even as Kirishima bought another cat tree for him, but Izuku quickly overruled and took that one over as well. Katsuki has surrendered to the new king in the house... At least the little cretan gave good cuddles, now twice Katsuki's size.
(They really quickly found out Izuku was a Maine coon from how big he grew.)
Katsuki still fought for his kingdoms, but a swift bap to the nose had stopped that.
The two lived (relatively) happily ever after. At least Katsuki was promoted to queen...