if bakugou and kirishima grew up together, can we really assume it would go well? i mean, kiri was a bit like deku in some ways, and if bakugou's childhood relationship with /him/ is anything to go by....
I’ve actually thought about this a whole damn lot - in the sense that this is an AU I’ve been thinking about for months and for a real long time I was super ambivalent about it because it could have actually gone both ways? It’s honestly one of the reasons why I found the idea so entertaining, since Bakugou is a complete asshat this might as well have been the only childhood-friends AU that could have ended my ship altogether hahaha incredible, usually that sort of AUs are all about the fluff lmao
Anyway now that I have Kirishima’s backstory I feel a bit more confident about the possibility of it ending well! Ah, this is assuming they’d always known each other like Deku and Bakugou have, but to be honest I think it could go fairly well whatever period of their lives they’d have met? The thing about Bakugou and Kirishima is that they like each other independently from their quirks, and that’s all the difference you need between their relationship and the one Bakugou and Deku have.
Bakugou likes in Kirishima the strength to stand up for himself and speak out and not let others walk over him while still never putting himself above others, his confidence and his trust in others and himself; Kirishima likes in Bakugou his one track mind towards his objectives, his strength both physical and psychological, his “live without regrets” way of going about life - these are things both of them have always had, quirks or not, UA or not. They’re also things that with time you realize aren’t actually true about them, but the first time they met, when they decided that they wanted to be friends, that was what they saw - and I think whatever age they met, that’d be what they’d see in each other anyway, so I think they’d still get along. Kirishima even said that he doesn’t mind Bakugou’s habit of picking fights left and right!
There’s also how Bakugou isn’t the type to judge a person based on how far they can push their quirks at the moment/how well they know how to use it - even a seemingly silly quirk can be a great one when properly trained, he isn’t stupid enough to look at Kirishima’s hardening and scoff at it. And be it Kirishima’s insecurities or Bakugou’s bullying, I think growing up together and finding their quirks together (even training together) might have actually made both of them better, in the end.
A Bakugou that’s just found his quirk would look at hardening, the one thing that can oppose him, and think “this is a strong quirk”. And when you remember that it’s not their quirks that got them to be friends in canon, in this scenario too Bakugou would already consider Kirishima worth it for other reasons, and that would mean he’d have no problems with telling him that he can do better, he can be better - and the younger you make them the more this is bound to end up well, imho. Same goes for Kirishima seeing Bakugou start acting like a bully, I think. He wouldn’t keep quiet about it, Kirishima, and even in canon Bakugou does stop being an ass when Kirishima tells him to quit it so, again, the younger you make them the more this should work, for me. Kirishima would be inspired by Bakugou, Bakugou calmed down by Kirishima, they would have probably just started their growth way earlier if they’d known each other as kids
Then again, it’s not like we know for sure. All I know is that Kirishima has liked Bakugou since the start, even though he had straight out told All Might that he thought Bakugou was crazy, and that Bakugou has only ever bullied Deku just because he couldn’t read him at all and that made him convinced Deku was making fun of him, which is a problem he would never have with baby Kirishima
It’s just optimistic suppositions tho haha