Shinsou didn't know what woke him up; but whatever it was, he wasn't getting back to sleep anytime soon. Glancing across the room at his roommate, Shinsou saw Mei's alarm clock glare 1:28 AM. Sighing, he hefted himself up and quietly left the room. "I think… I think I need something to drink." Shinsou thought to himself as he tiptoed down the stairs to the main floor, where the kitchen and the first dorms were. As he entered the common room, a small sniffling caught his attention. "Intruder!" His instincts screamed out. It was too close to the Overhaul Raid to be a coincidence, but Shinsou forced his heartrate down. "Nonsense," he thought to himself. "I'm overthinking things. Lets see what it it first, shall we?"
Rounding the corner, Shinsou ran into someone; or rather, the other way around. There was a gasp and a small thump as whoever turned the corner hit the ground. Looking down, Shinsou saw Eri, Yuuei's resident angel and the unlucky objective of the Overhaul Raid. "She's crying..." Shinsou noticed, as he knelt down to her level. "Eri, are you okay? I didn't mean to make you fall." Eri looked up at Shinsou and swiped at her eyes with her sleeves. "Sorry," she half-whispered half-whined, sniffling. "Have you seen Big Brother Deku and Big Sis Ura? I can't sleep, and they said I could sleep with them if I have nightmares."
Shinsou smiled and patted her head, holding out a hand for her to take. "Izuku and Uraraka aren't here right now, but they'll be back in the morning. Do you want some hot chocolate? I know it helps me sleep." Eri nodded and took his hand, walking with Shinsou back to the kitchen; where she sat on one of the couches and watched as he made the boiling water and added the chocolate mix. As he padded around the kitchen, Shinsou hummed under his breath; an old song he remembered his mother singing to him when he was little.
"Big Brother Shinsou," Eri asked, yawning slightly. "What's that song?" Shinsou handed her a mug of hot chocolate and sat next to her, draping a blanket over the two of them. "Just something I remember from a while ago; when I was your age." Eri thought about that while she sipped at her drink. "Do you know the words?" She asked after a while. "I think it sounds nice." Shinsou scratched the back of his neck. "I can try, if you want..." He offered. "But only if you go to bed after, okay?" He smiled. Eri nodded and scooted closer, placing her mug of hot chocolate on the side table next to Shinsou's. Shinsou wrapped them in the blanket and held Eri close to him, her head against his chest; and started humming the opening of the song.
"For the honey and the thistle… For the bitter and the sweet… For the precious little girl who made our lives complete..." Eri snuggled closer and Shinsou continued, singing softly to her.
"For the fire, bright and blazing… For the water and the foam… For those who journey onward and now come back home..."
"Guard what little I've been given… Guard the hill my child could climb… Let the fruit that's yet to ripen be left until it's time..."
"As the wind breathes through the branches… And the star falls in its arc… All my dreams and my desires form crystal shapes out of the dark..."
As he finished the last verse and hummed the closing, Shinsou glanced down at his young companion. Eri was sound asleep, leaning against his chest; her hair fanned out behind her. Shinsou readjusted himself so he was lying lengthwise on the couch on his back, with Eri lying on his front; and kissed her head. "Goodnight, Eri. Sweet dreams..." He mumbled as he felt himself drifting off.
BONUS SCENE:
"Come quickly! No, wait! Be quiet; you'll wake them!" Hushed whispers and excited squealing were what woke Shinsou the next morning. He opened his eyes slowly, adjusting to the light, and saw the majority of Class 1-A gathered around him; phones out. "Can I help you?" He mumbled, yawning. Glancing down at himself, Shinsou realized what all the fuss was about: Eri was sound asleep, hugging his chest like a pillow. He smiled and stroked her hair, earning even more squeals from the class; especially Hakagure and Mina, who immediately started recording. Even Bakugou smirked, the normally hard lines around his eyes softening imperceptibly.
Just then, Midoriya and Uraraka burst in the door, out of breath and still wearing their costumes. They pushed their way through the small crowd until they got a look at the centerpiece. Shinsou smiled and offered a small wave. "She was really worried about you two, you know?" He said softly, careful not to wake Eri. "Try to let her know next time, okay? Now go shower and rest; you've earned it." The pair nodded, relieved, and split to resume daily life at Yuuei; the rest of the class following suit.
Shinsou lay back down and absently stroked Eri's head. "Life sure has changed for us, huh?" He thought, as he settled back down and closed his eyes. Feeling Eri hug him tighter, Shinsou smiled. "And I wouldn't have it any other way."