#sibling!au

One time, when she was three, someone pushed her on the playground, and Katsuki nearly punted a four year old- he, instead, told her how to push back (which wasn’t appreciated by his parents) and stand her ground.

However, said ‘happiest brat mantra,’ she knows exactly how to make it curve him for her benefit.

When he’s left to babysit her, she flashes him her biggest set of puppy eyes to make him play with her; his parents have come home god knows how many times to him with a table cloth draped over his back, playing Horsies- she does it more when Midoriya is the horse, because he can’t say no to her either, but anytime she says “Zuku-ni would do it” to Katsuki, he immediately drops on his hands and knees with a snarl on his mouth. Like hell he’s gonna let Midoriya win her heart like that.

And listen, the kid is cute, and she’s got that classic Bakugou charm. She knows how to work it! But Katsuki can’t help the absolute rage down his spine when she’s got her tiny arms curled around Kirishima’s thick neck and they tease him about when they’re gonna get married because yeah, of course, she wants to marry his friends, because why can’t she be disgusted by them like he is?

(”Yeah, bakubro, you’re cool being my best man for it, right?”

“I’d rather skin you alive and drape you over my banister before I let you come near her with a ring pop, do not test me-”)

But obviously, no matter what, for Kaida’s happiness, Katsuki is willing to move boulders, move mountains, part seas, and swallow the stars if it meant she would smile for him.

So, when he gets taken by the LOV, it’s wild how much Kaida deflates. Mitsuki catches her, more times than not, curled up on his bed to sleep for her nap, and at nighttime, she stares longingly outside of her window to wait for him. They try to be gentle and explain that he’ll be back soon, but she doesn’t believe them, she wants to see it with her own eyes.

They put her back to bed, but she’s up a few hours later, perched at her window and whimpering softly. They try to keep her in their bed, but all she does is ask questions about Katsuki until the early hours of the morning, things they don’t always know the answer to.

Those were the longest days of her little life, and when they finally get the call that he’s alright, he’s alive, it’s an extremely tearful reunion. And Katsuki, the hellion and wall of impenetrable rage, screws his eyes shut to fight the stabbing of tears that want to fall into her hair.

Kaida absolutely refuses to let him out of her sight after that.

The entire time they’re talking to the school, her big, crimson eyes are blinking up at him, tiny fingers curled in his shirt collar. Completely unfazed by the snapping between her parents and brother, she just. Stares. She doesn’t smile, she doesn’t frown, she doesn’t pout. It’s just a simple, blank face with all her emotions and relief in her eyes.

Even after the whole ordeal, there’s a part of Kaida that treasures Katsuki (somehow) even more. Anytime he’s home, she’s clinging to him, be it physically by dangling to his back and legs, or simply being in the same room with him: next to him at the dinner table, sleeping on his bed while he’s at his desk, playing with his fingers while he watches tv.

He’d be annoyed by it if she wasn’t so cute.

If he didn’t miss her almost as much as she missed him.

It’s different when he’s away at school and can call her whenever he wants; he hates how much he loves the little snot.

Even now, curled into his side and sucking her thumb while they watch TV, Katsuki knows that if he gets up to merely pee, she’s gonna follow him and sit on the outside of the door, talking to him under the door. (The first time Deku saw that in action, he cooed audibly, and Katsuki nearly ran out of the can with his pants undone to blow him to shit.) and he’d never be able to complain about it.

Sometimes, he can’t help but putting off whatever it is he needs to do, to keep her comfy.

It’s what big brothers do.

“Katsu-ni?” She hums around her thumb. Big eyes look up at him, and he scratched her hair gently.

“What’s up?”

She pauses, as if trying to find the words, her tiny brows furrowed in thought. Then, she speaks, words warbled from the digit in her mouth.

“You think mumma gon’ notice if I go back ta’ school wiff you? In your back-packie?”

He snorts and tightens his arm around her, burrowing his face in her hair to hide the sound. She squeals and bats him away affectionately, completely crawling in his lap when she deems he’s too far from her.

“I think she might, stink.”

Kaida pouts and thunks her head against his chest, the fingers of her free hand fisting his collar. “Do ya have to go…?”

“You know I do,” he grumbles, hooking a lock of hair behind her ear, once again burying his face in her hair. The only noise for a moment comes from the TV, and he focuses on the rhythmic breathing from his little brat.

“You don’t have to think about that for a few more days,” he says, planting a kiss to her head and choosing to fight the way his eyes water when she sniffles softly. “You can use me as a jungle gym for a few more days.”

This, has her giggling, and he angles his head up at the ceiling because this is always the hardest part about being home, especially since he was kidnapped.

“I don’t like when you leave, Katsu-ni,” she mumbles.

“I know, baby.”

“Make me miss you…”

“I know- you know I miss you too.”

“Wish you didn’t have to keep goin’ ‘way…”

He swallows again.

beidou’s a super chill sister and likes to joke around and include you in everything

however she’s very protective and doesn’t let anyone lay a finger on you

although she relaxes and acts like herself around you, she still keeps up a tough and strong demeanor and tries to look reliable

she doesn’t come home often, but she never forgets to get a gift for you

usually it’s a trinket that she found or bought on her adventures

sometimes she comes with a new recipe or a piece of jewelry

“you gotta try out this recipe i got from ritou! you’ll love it!”

she always makes sure you ate or have enough to eat (a result of not having enough to eat when you were younger)

“y/n, did ya have breakfast yet? hey, come with me and the crew! i’ll treat ya to something good!”

she and you both love xiangling’s cooking, so whenever beidou’s back in liyue, you almost always eat out at wanmin restaurant

beidou swears like a sailor [ hahaha ] but whenever you’re around she tries to hold back. once you’re until “old enough” she lets loose

but sometimes you have to take care of her too like holding her back to avoid fights with people (kind of difficult because we know beidou’s buff as hell)

“come on! y/n, let me at ‘em! i swear i heard ‘em talk smack about you!”

as for the crew of the crux, they’re also super sweet to you and treat you as if you’re a part of their pirate family (but beidou’s always watching just in case)

kazuha thinks it’s funny how you somewhat resemble your sister, but at the same time you’re so different from her

“what’re you two talkin’ about? he’s not saying weird sh- stuff to you is he? i might like this kid but i won’t hesitate to take action if i need to.”

ningguang thinks you’re cute, she adores you so much that sometimes beidou thinks ningguang likes you more than her

i want to think that ningguang kind of spoils you really subtly like every now and then she gives you a small gift like fabric or something

“hey hey, y/n, you can’t just take the tianquan from me like that!”

“there’s enough of me for the both of you.”

on the sibling scale, she’s a solid 9/10

“y/n! ah it’s been so long, how about i treat you to something, eh?” beidou waved to you as she walked down from her ship.

“wanmin restaurant?” you suggested, already knowing the response that would follow.

beidou laughed as she slung an arm around your shoulders, leaning in for a half-hug. “nothing but the best! we’d better get going though, we don’t want to be late to xiangling’s cooking!”

as the two of you walked from the docks to chihu rock, you started to make some conversation with your older sister about her latest adventures. she had sent you a letter a week earlier detailing her adventures of looking for treasure on some smaller islands on the coast of tsurumi island. the fog had apparently been too thick to venture to the main island. but now she was excitedly telling you about what she had found.

“lots of mora, of course, and some crystals. there were also those electro sigils which my men and i traded off a portion of. that reminds me, i got a little something for ya!”

you looked up at her in expectation. “what is it?”

beidou chuckled as she fished through her pockets, “i’m sure you’ll love it. let’s see… here we go! first of all, i got you some of these sakura shrimp crackers.”

you took them from her hand and opened up the cloth wrapping they were in. you expected a fishy scent, but you were surprised that it pleasantly smelled like sakura flowers. the bright pink color reminded you of those sakura blooms that beidou sent to you once.

“then i got you a recipe for dango milk and fluorescent fungus. pretty cool right?”

you grabbed the rest of the goods and smiled up at her. beidou had told you great things about dango milk and you had been awaiting the recipe to try it out for yourself. as for the fluorescent fungus, maybe they’d make for some good decor? you weren’t sure, but you put it away.

as you neared wanmin restaurant, you could already smell the delicious food. before beidou’s ship docked, you had already run over to check to see if xiangling was there and you asked if she’d stay a bit overtime since beidou would be eating. xiangling, being as excited as ever, agreed and said she’d start working on her special as well as some of beidou’s favorites.

“captain beidou,” xiangling called out, waving enthusiastically, “have a seat! i heard you were coming home so i prepared some dishes for you, enjoy!”

you and beidou took a seat next to each other as xiangling pushed out dish after dish in front of you. beidou was definitely happy and savored each bite as she told stories to you and xiangling. they weren’t exactly like the exaggerated tales that were shared around liyue, but they were still compelling nonetheless. every now and then, she would ask if you were eating and you’d have to take a bite of xiangling’s delicious cooking to convince her that you were.

but (somehow) you eventually finished all of it and thanked xiangling before heading off to take a light stroll around liyue. you caught your sister up on the latest news and greeted some people since it had been a while. the day ended with some dinner with the crew and kazuha, and then you and beidou went home.

“hey, we should hang out like this more often!”

 Scenario 1

If you are related with Yuto and Minkyun is the new join

Could you be are extroverted and you kind off help Yuto to get close to Minkyun

You and Yuto would find this new brother fascinating. He looks quiet at the beginning but later he will prove you both wrong

But when Minkyun is his serious mode, you will feel strange towards that too, because how can he has such large gap

i thinking its super cute and funny that if you and Yuto both gets intimidated at Minkyun’s height lol

It will be fun if Yuto has a denial stage aka hard time opening up to accept it because he is cautious, but you just bluntly accept it and joins Minkyun. It shows difference between personality of related blood siblings lol

IF actually you and your blood brother are introvertedly fun, Minkyun’s existence will be the key to spark both of your dork traits. It is a assuring factor for your parents that you 3 hang out very well.

its not like your family never heard Yuto laughed, but ever since Yuto and Minkyun opened up and gets close, Yuto is laughing alot.

you and Yuto both asking MInkyun for help when you two could understand some Koreans. But since Minkyun fools around 50:50, you two ends up googling or just straight up asking your friends

But if it is homework/grammar wise, Minkyun will really really explain it to you.

Minkyun also get close towards Yuto’s classmate, Minseok. I think a few times, you did not join, but the boys went out to roam the streets to feed stray cats/animals.

Bonus if in this hc, and you are younger than Yuto, and you have a crush on Minseok. Minkyun picks it up and would wanna help out but you told him to keep still XD

you three gonna be game buddies for sure lol

Scenario 2

If you are related with Minkyun and Yuto is the new joined / OR my preference, Yuto being the home stay student, and your family ends up unofficially adopts a Japanese sibling since Yuto continues his homestay contract with your family.

You and Minkyun thought Yuto is a bit distant in the beginning, and you three overwork your brains on trying too hard not to do something impolite towards each other culture.

But you and Minkyun would be surprise at how Yuto is so adapted to Korean culture later on.

Could be you are similarly shy like Yuto and need time to open up. This time Minkyun will be the one to open up first and slowly helps you.

Minkyun would suggest 3 of you to hang out at pet shelter. It does help.s

hould it is the homestay hc, I do see your family and Yuto’s family going along very well. Occasionally showing up to greet Yuto’s family during Skype session.

As Minkyun is the one who gave up, you are the one who would pick Japanese up later on. It gave Minkyun a shock when you and Yuto casually switching Japanese and Korean (with you amateur Japanese, but its already enough to give Minkyun a fright)

He might pout a bit, thinking/semi blaming himself a bit for not putting more effort to try to manifest the tool get close with Yuto. But then will throw the worry aside because its not really that important. Because he understands that its not like he and Yuto could not communicate anyways.

if it is the student hc, This could be when you and Minkyun are still high shcool-ers/ middle school-ers. And your school opens for foreigns students.

Minkyun being a bit worried because of he is 95er and Yuto a 99er. But when one day he sees Minseok come to visit, he goes: “ OMG thank goodness, I was so worried that he could not get along with classmate.”

Yuto just sidelining his hyung lol like chill dude, I interacts just fine ok. Don’t worry. 

(maybe Minseok comes to pass homework for Yuto because Yuto was sick and Minseok know the address.)

Similar to above, should you are Minkyun’s younger sibling, he can picks up that you have a crush on Minseok too.

Scenario 3

If you are the child that born later from your parents marriage

Them both flustered when they first meet the baby you.

Idk why for this hcs, I felt that age gap will be wider, as Yuto and Minkyun’s parents come together when them both are more older than other hcs. My age range idea is Yuto is about 10 or 13 while Minkyun is 14 or 17.

So, also I do think them both had a fight with parents, especially the mom because of her decision to get pregnant at older age. But quickly reconciled, they are just worried, no bad intentions. 

Because they are more grown compared to other hcs for this scenario, they help out on babysitting even more and even practical.

Minkyun basically is just like a young flustered dad while Yuto is the calmer one. But sometimes when the baby you throws a tantrum because you specifically wanted mommy, cues in both  Minkyun and Yuto flustered.

Also, Minkyun being funny but you are unbothered, 3 seconds later, it was Yuto who could not hold in and burst out laughter. 

You might be the one who pick up the language. And because you master both language, maybe later on your career pick would be interpreter

Rather than Yuto gets confused with language, you are the one who gets confused with language  in the beginning lol

It only got better when Yuto decided that you should speak Japanese with him and Korean with Minkyun in the household.

Minkyun is gonna let his baby young sibling ride him, and he will do his iconic either elephant or horse voice imitations.

(super funny bonus, if you are scared of that when you are a baby, but it got better later on.)