kirishima has a chewing stim (sharp teeth that regrow often; lots of pain) and he ends up accidentally ingesting a lot of non-edible stuff (ie: pencils, pens, ink, fabric, basically anything) so bakugo starts looking for ways to curb his habit. +

bakugo's probably not diagnosed but is on the spectrum, while kiri's diagnosed aspec and adhd. baku's never really had experience with or recognizing stims, so he assumes kiri's chewing stim is actually just a habit- one he could, hopefully, break. +

he starts by swatting kiri with a rolled-up packet whenever he sees him chewing on something. of course, this doesn't really stop him. as soon as he stops gnawing on something, his focus is out the window. the nervous fidgets, daydreaming, wandering eyes, all begin. +

bakugo's ticked at himself because he just *can't figure out why this habit isn't breaking*. so, reasonably, he goes to the internet.

"stupid friend cant stop chewing on pencils"
"chewing on inedible things"
"chewing on things subconsciously NOT a habit"
+

After a bit, he stumbles upon a website talking about adhd. now, baku knows kiri has adhd (this was, as he found out, why he had such trouble in class), but he hadn't really given it thought other than "kid can't focus". Apparently, it was so much more than that. +

he spent a good few hours perusing websites talking about adhd, nervous tics, attention spans, and stimming, among other things. in the process, he ended up learning a lot about his own habits.
+

And, by the end of the night, he had found a way to finally stop kiri's obsession with inedibles.
+

A few weeks later, a package arrived at the dorms. Instead of opening it immediately, though, bakugo scratched his name off the delivery tag and wrote in thick, black sharpie:
"to shitty-hair"
+

A few moments later, when kiri returned from his evening workout, he was met with the unassuming cardboard box. He could hear kiri's laugh from outside the door before he heard the knock and subsequent "Hey, bro! Is this from you?"
+

bakugo scoffed and faced the door, yelling, "Who else, idiot?"
Another laugh, and then the doorknob was turning. Despite not even opening the box, kirishima was already beaming; his tan skin reddening as he looked from the package, to bakugo, and back. +

Kicking the door shut with one foot, kirishima moved to bakugo's bed, across from the desk where he sat. Hardening one finger, he made quick work of the weak packaging and quickly began ripping through layers of decorative paper. +

bakugo looked away; he really didn't want to see kiri's reaction if it ended up being something he disliked.
He waited.
And waited.
And then, sniffles.
+

bakugo whirled around on his desk chair, coming face to face with an utterly sobbing kirishima. His eyes were scrunched up and his teeth were bared in a smile.
"bakugoooo," he cried, jumping up from the bed to embrace his best friend, "This is so awesome! Thank you!"
+

Now, bakugo wasn't a fan of hugs, not at all. But his best friend, arguably his *only friend*, was sobbing, and he really didn't have the energy to be mean, not when he was so proud of his idea and the result he got. Still, he tch'ed, weakly pushing at his shoulders.
+

"Fuck off, shitty hair," he muttered, "This is just so I don't have to keep buying more pencils to feed your lead addiction."
kirishima laughed and turned around to grab the item out of the box.
+

It was a thick, rubber necklace shaped like a shark, bright red and shiny and, as the packaging suggested, "immune to cuts, tears, and punctures."
When bakugo saw it suggested on the website he first found, it was an automatic purchase.
+

As kirishima investigated the toy, bakugo began to speak.
"I thought you might've, I don't know, wanted something better to chew on other than pencils and pens," He paused, thinking, "I don't know much about your adhd thing, but... if it helps you, that's fuckin' awesome."
+

kirishima turned around and smiled, "I never knew you were so observational!" He laughed, "Thank you, though. It means a lot to me that you'd buy this... let me get you lunch this weekend, as repayment!"
bakugo scoffed, but nodded.
+

He didn't need repayment; seeing his best friend thrive was enough of a gift on its own.

[end]

[ honestly, i didnt mean to make this a full thread! but this is absolutely all projection and idk. i havent written in a while so be gentle LOL. the stim toy i described is based off the toys available here:
https://www.stimtastic.co/stim-jewelry 
anyway, i hope y'all enjoyed! ]