Chapter Text
They're sprawled out on the floor, side by side as Katsuki explains the plan to Deku.
“And once we're officially superheros, then we’ll get married, so we can live together. It makes sense to have our secret base at our house where we can keep an eye on things.” Katsuki finished, proud of his plan as he sketches out the super secret hidden door that would hide their lair. He can't wait to see the look on the nerd's face when he puts on the finishing details.
“You promise, Kacchan?” Katsuki takes his eyes off the page, capping the marker with a snap as he looks over.
Deku is sitting on his hands and band-aid covered knees, markers and crayons and construction paper littering the floor around them. His big green eyes are fixed solely on Katsuki, exactly where they should be. His big baby cheeks are ruddy red, interrupted only by a smattering of freckles and sticky grape juice stains from snack time.
Gross.
“I don’t say things I don’t mean, stupid Deku. Of course, I promise. You have to promise too!” Katsuki points at him with the marker in his fist, a furrow in his brow at the idea of Deku not keeping up his end of the bargain. Of course they would get married and be hero partners. They already decided this, why did stupid Deku keep asking? The four year old rolls his eyes once he realizes the other child has started crying.
Again.
“I-I p-promise, Ka-Kachan, we’ll b-be superheroes together for sure!” Deku’s crocodile tears spill over, despite the huge smile missing a few teeth here and there.
He’s almost cute for a second, and then he immediately begins snotting into his own nasty sleeve.
Gross.
What an idiot.
He’s lucky Katsuki tolerates him.
Life as Katsuki knew it hasn’t been the same since he met Deku.
It was just another boring day.
Nothing special about it at all.
Katsuki was playing by himself, like usual, when his mom knocked on his door, and introduced him to her old school friend and her brat.
“Hey Kats, there’s someone I would like you to meet. This is my friend from school, Inko, and her son, Izuku.”
“So?” He didn’t look up from his blocks, intent on building a suitable size city to demolish in a villain attack later.
“Oi, don’t be a brat! That last babysitter took off like a bat out of hell after one day. You’ve terrorized the neighborhood, so I'm out of options. Inko, the angel she is, has volunteered to keep an eye on you when your father and I are held up at the office. Maybe with another kid around you'll be less of a handful!” That got his attention. His mother was a bigger, bossier version of himself. The same ash blonde hair, carmine eyes, and sour expression he saw in the mirror was reflected back at him now, obviously older and more feminine, but it was annoying that he couldn't even make fun of her face without essentially making fun of himself, she must have done it on purpose. Now, his mother had crossed her arms, domineering in her posture, already prepared for the tantrum she was expecting.
He met her gaze, so like his own, pointed his chin up indignantly and scowled.
“I don’t need a babysitter, I’m old enough to watch myself!” He snapped, baring his teeth at her like that documentary showed him. He was going to be the boss of this house one day, why not now?
“Try telling that to a judge.” She scoffed, rolling her eyes and clearly not taking him seriously. Katsuki didn’t reply to his mother's comment. After failing to intimidate her, he chose a new target.
Inko giggled a bit behind her hand, clearly finding his snarl funny for some reason, but doing her best to be polite. She was... okay. Her hair was green, and pulled halfway up and halfway down. She was shorter than his mother, a little rounder too. Looked like any other lady to him, but the thing hugging her leg was different.
The boy, “Izuku” apparently, was hardly impressive. He was small, skinny with knobby knees and wild green hair. It looked like he'd never brushed his hair a day in his life. He had dirt on his face, like he had gone digging in the garden - wait no, those were freckles on his cheeks, not dirt.
How ugly.
His trembling hands clutched his mom’s skirt, partially hidden by it and the door. He was peeking around like he was worried Katsuki was going to bite his head off. So maybe not a complete idiot.
Katsuki glared at the other boy in challenge. Izuku squeaked and hid a little more, teary eyed and hiding from Katsuki's gaze until his eyes finally shifted enough to see the hero posters on the walls of his bedroom.
With a wet gasp, and the biggest sparkliest eyes Katsuki had ever seen, he dropped his mother’s skirt and took two small steps into the room.
“H-hi, I’m Zuku, and I like superheroes too! Do you like A-All Might? All Might is my f-favorite superhero and not just because he’s big and strong and smart! Sometimes I like to...” The kid just kept going, sometimes speaking too fast to understand, mumbling and listing off different characters and their quirks, stuttering all the while, muttering about his favorite episodes. It took a while for him to realize Katsuki hadn’t actually answered the first question, and when he did notice, his face turned bright red, reminding Katsuki of a strawberry.
Something about that was funny, he thought. Different.
Different from what, he wasn't sure, but he knew it was, all the same.
Katsuki couldn’t care less about having a playmate at first, of course, he just pretended the other kid wasn’t there. He'd figure it out eventually and stop showing up if Katsuki just ignored him long enough. The first few afternoons they came to visit, Katsuki just played by himself, like usual. The boy didn’t seem to notice the cold shoulder though, always following him around, yapping about something or another. He's not sure when he started answering back, when he started caring.
Some things became obvious quickly.
1. Izuku was a dork.
He was obsessed with heroes. Especially All Might. Katsuki’s favorite hero was also All Might, but Izuku liked all the boring stuff. The cats stuck in trees, saving people and carrying them around, even the episodes with no villains at all. He liked writing notes and collecting useless information, (who cares what Crimson Riot’s favorite food is, really?) Katsuki preferred the punching and the super powers, thank you very much.
2. Izuku was an idiot.
He couldn’t even say Katsuki’s name correctly. The kid blamed his missing front tooth for his lisp, but Katsuki knew better. After the hundredth time of listening to Izuku butcher his name, he blew up at the other, and ended up stuck with ‘Kacchan’. Another day, when they were scrawling their names on some coloring pages, Katsuki realized ‘Izuku’ could be read like Deku.
There, now they both had a dumb nickname.
Deku and Kacchan.
The “wonder duo” according to the Old Hag and Aunty. He thinks they mean it in a sarcastic way, but he doesn’t care, it sounds cool.
Where was he?
Oh right, 3. Deku was a crybaby.
He was always crying about something. About ladybugs being squished in the grass, about loud noises, about the weather, about episodes of All Might he’d already seen a hundred times, about his sandwich being cut into rectangles instead of triangles. If it happened, the kid probably cried about it.
He also cried because of Katsuki.
Even though the other boy was a crybaby, he wasn't a tattle-tale. Not when Katsuki chose all their games and made himself the leader, not when he yelled at him or called him names. Not when he accidentally pushed Deku down or tagged him too hard. Deku always forgave him. He would whine about it for a while but five minutes later he was back to doing whatever Katsuki told him to, following behind him all the while.
Deku never complained to their parents, and he always came back, no matter how much he cried, or how loudly Katsuki told him to go back to his own house. Like some sort of disease, like a barnacle on Katsuki's ship.
His parents were busy often, it was sort of lucky that Deku’s mom showed up when she did, because those days with all those annoying babysitters were boring.
Plus, he had to admit that the food is way better with Aunty around. His old hag couldn't cook to save her life, and while his dad wasn't awful at it, he was too busy to spend hours in the kitchen.
They both were, honestly. It's not like they had serious jobs, they just drew clothes and played dress up, nothing dangerous; but whenever there was a show or a gala his parents were gone before he woke up and were back late, way past his bedtime.
Whatever, they were boring.
Aunty Inko makes all her food from scratch, nothing like the lukewarm takeout his folks brings him on their way home, or the boring baby food the babysitters would microwave for him. Aunty bakes cookies shaped like little All Might’s, and lets him lick the spoon after she’s finished with it. She cooks with real spices that burn his nose and tongue, and he loves it. She even makes bentos for his ungrateful parents and extra portions of dinner for them to enjoy long after he and Deku have fallen asleep.
That was another thing that was different.
Before, he always slept by himself, but Deku, the crybaby, always ended up wiggling his way into Katsuki’s bed when he had to sleep on the futon. The first few times, he was upset about having ugly Deku’s drool on his pillow, grossed out and convinced the nerd would wet the bed or something.
On the nights he had to sleep alone though, he found himself missing the warmth of the clingy boy. The bed felt uncomfortable… too large, too cold, and empty. The shadows seemed darker, more insidious without small snores and grabby hands to hold onto his in the dark.
Now he has a… well his old hag called Deku his “friend” but Katsuki knew better. Deku was his partner, his sidekick, his wife.
The word ‘Friend’ wasn’t really applicable here, but the adults weren't very good listeners.
Between sleepovers watching All Might cartoons, playing super heroes in the park, drawing and coloring their costumes, not a day went by where Deku wasn’t by his side.
They shared snacks and juice boxes, camping trips, and afternoons at the playground. They pretty much did everything together.
There were balmy summers clambering through tall grass to find cool looking bugs. Fireworks bursting over their heads at the beach, squished together on a blanket with Aunty, shoving their feet in the fine sand to feel it between their toes. The smell of sunscreen and popsicles melting onto the concrete beside chalk drawings.
Birthdays side by side with Deku, blowing out candles and making wishes on stars. Carving pumpkins to look like All Might, and telling scary stories under a blanket with a flash light.
Their first festival, and the ones that followed after, watching the fish swim in their bowls, playing with sparklers and competing in carnival games for stupid prizes. Aunty cooking mountains of food for Christmas, with perfectly wrapped gifts in color coordinated wrapping paper.
Green for Deku, Orange for Kacchan.
Their families all bundled up in coats and mittens, holding hands as they walked to the shrine on New Years Day.
Through everything, Deku was never far behind him, always one hand buried in his shirt and eyes on his back.
It’s a good thing, too. Deku is useless on his own. Always lets the bigger kids push him around, and lets the adults talk down to him. He’s a whiny crybaby, and normally Katsuki refuses to play with crybabies, but Deku is different.
Katsuki isn’t sure how yet, but he’s for sure he’s going to figure it out.