Reader is gender neutral.
"Have you seen (y/n)?" Kirishima asked, feet propped up on the couch cushion, a licked-clean popsicle stick poking out of his mouth. "I figured they'd be back by now."
Kaminari shrugged, flipping through the channels of the communal TV in the shared living space. "Nope. I wouldn't worry though. Probably spending the night with their folks. They had dinner there, right?"
"Ah, yeah, you're probably right," Kirishima replied, scratching the back of his head. He relaxed into the couch, setting aside the gut feeling that something was wrong. It was nothing.
After a while Kirishima heard the echo of thunder outside, the pitter patter of rain hitting the roof of the dorm. Suddenly the front door flew open. Turning his head from the TV he saw you, dripping wet from head to toe.
"Wh- hey! You're back? I thought-" Before he could finish you bolted out of the room towards the dormitories, the pained look on your face making his brows furrow. "Hey! Wait!" Krishima leapt over the the couch, running after you. He knew something was wrong, and this confirmed it.
"Dude!" Kaminari yelled after him, but Kirishima already rounded the corner and bolted up the stairs after you.
He followed the damp footprints in the carpet down to your room before he stopped. You were trying to open your door but struggled with the key in your wet hands.
"What happened? I thought you were with your parents," Kirishima called down the hallway. His voice caught in his throat as you turned to him, wet hair sticking to your face, eyes full of pain and hurt.
"Just leave me alone!" You screamed back. It probably woke up anyone who was asleep at this hour on your floor but you didn't care. As soon as the key slid into your bedroom door you tossed it open just as Kirishima sprinted down the hallway, but he was too late as you slammed the door closed in his face.
"(y/n)! You can talk to me!"
"Go away!" you cried through the door. "Please...Kirishima just go away. I don't..i can't talk about it right now."
He was about to pound a fist on your door, but decided against it, letting his hand fall like dead weight to his side as he stared at the painted bedroom door.
"Just...text me I guess. I'm not far away..." he muttered, just loud enough for you to hopefully hear. With a sigh Kirishima walked back down the hallway, past Kaminari questioning him from the the couch, straight to his own bedroom where he locked the door, phone turned on in case you wanted to talk.
It didn't buzz all night.
The next few days were concerning, and Kirishima wasn't the only one who noticed your tired and listless behavior. You were sluggish during training, which Aizawa called you out on. You ate lunch alone, pushing away anyone who offered up a seat. You brushed off friends who just wanted to make sure you were alright.
The weekend rolled around and Kirishima finally put his foot down. He felt like a shitty friend, unable to talk with you about whatever was going on. It was obviously something bad since it affected your mood and behavior in ways everyone noticed. He took out his phone to text you, and wasn't going to accept 'go away' as an answer this time.
K: I'm coming over, please just let me in
He picked up your favorite snack from his desk - he'd gone to several different stores after class to find it - and made his way to your dorm. Softly knocking, he waited.
"It's me," he said, though he assumed they knew who it was already. Finally he heard the latch on the other side unlock as the door slid open. He couldn't hold in the surprised expression when he saw your face, tired and worn and just...small. Realizing he probably looked like a jerk with his mouth hung open, he straightened up and extended the snack out to you.
"I uh, brought you something. To cheer you up!"
"Oh...thanks. You can come in. I think..." you hesitated, but the bright look on his face pulled you in. "I think I'm ready to talk now." With that Kirishima nodded and walked into your room as you closed the door behind him.
He noted the trash can full of used tissues, and a freshly opened tissue box next to your bed. This wasn't good.
"So...just lay it on me, say as much or as little as you want. I'm not going anywhere," he said, sitting down on your bed and patting the spot next to him for you to sit down as well. You did.
You sniffled, fingers fidgeting in your lap, eyes avoiding his gaze. "Shit...where do I even start. Uh...so you know I was with my parents the other night. I was going to say after dinner. Catch up, you know. They're worried about us with everything happening with UA and all that..."
"Yeah," Kirishima agreed, scratching the back of his neck. "My folks are on my case too, constantly telling me to be careful, stay alert, all that stuff."
"Mm, yeah. Anyway...during dinner, uh, they brought up dating, asked if I had anyone I was interested in...dumb stuff that's really none of their business, ya know?" Kirishima didn't miss the heat rising to your cheeks as you spoke, but he felt his own face warm up as well. They were so busy with training and villain work that honestly dating wasn't on his top list of priorities, but the idea occasionally flickered across his mind if it was with the right person.
"Ok, dating, got it...so what happened then?"
"Uh..." Your lip trembled, knuckles turning white as your nails dug into the skin of your palm from tension. Suddenly another hand covered yours.
"Hey, it's OK. Whatever happened can't happen twice, and especially won't happen while I'm here." His eyes were so gentle and accepting and patient; they spurred you on.
"We got into a fight about it, the pressure was a lot and I just didn't want to deal with it and then I suddenly just...shouted 'what if I brought another boy/girl home' it just sort of came out hah I was pretty riled up I guess and they were just silent for a minute -"
"Wait," Kirishima said, interrupting your story. "Do you like...?" Your cheeks flared up with embarrassment, but you nodded.
"I uh...I like both. I think boys and girls are cute, I'm attracted to both...is that...?" You looked at him with pleading eyes, asking him not to yell at you or think you were a bad person.
"No way! I'm bi too! Bi buddies!" He broke out into that beautiful grin of his and you couldn't help but mirror his smile after registering his words. You weren't alone, and he didn't judge you. "But anyway! Sorry for interrupting..."
"Oh..." you bit your lip, breaking eye contact again. "They got...really mad. Yelled at me. They pretty much kicked me out, called me a b-bad person..." a sob escaped you remembering their harsh words. The love of a parent was supposed to be unconditional, but apparently their love didn't reach very far. "I don't...I can't go back, Kiri. I don't have a home anymore-"
"That's so-!!" Oh he was steaming mad now, hearing you cry and what your parents SAID TO YOU!? It was beyond unmanly, it was downright wrong! He grabbed your shoulders and turned you to face him on the bed, the heartbroken look on your face spurring him on.
"Listen to me (y/n). You're super awesome and strong and smart and GREAT, OK? And if they don't like who you are or who you like, then that's on them and they have to live with making you feel bad. But you're NOT a bad person, got it?" Shaking nervously, you nodded, acknowledging the words of a friend. "They might be family, but they're not family, understand? Your friends and the people who support you no matter what are your family, like me! And uh, everyone else!" He tacked on the last bit quickly.
Before he knew what was happening you jumped forward and enveloped him in a crushing hug, burying your face in his arm. "Thanks, Kiri...I really needed to hear that. You're the best."
Though your voice was muffled he heard every word, managing to get one hand up and pat your lower back. "No problem at all, I meant it all. And! Though my folks can be kinda lame sometimes, they're pretty cool overall. You can eat dinner with us if you want!"
You pulled away, a smile tugging at your lips as you wiped the drying tears from your eyes. Kirishima grabbed the tissue box from your bedside table, holding it out for you.
"Oh yeah? You finally gonna force-feed me all those old Crimson Riot movies?"
"Oh hell yeah you know it!"
The rest of the night was spent with laughter and delicious snacks. It felt overwhelmingly good to know that someone had your back, that they didn't think of you differently, that they weren't going to yell at you or kick you out for being true to yourself. You were grateful, and you were happy.