You sat sideways on Yunah’s lap, your cheek pressed against her shoulder, body heavy and loose with exhaustion. Her pencil scratched steadily over the worksheet on the desk in front of you both. You could feel the slight movement of her knee beneath you as she adjusted her posture to get more comfortable, but she never asked you to move.

Outside the window, the sky was that strange shade of dark blue that wasn’t quite night, but had clearly left day behind. The desk lamp’s yellow light hit the paper sharply, casting your shadows across the page. Her voice was soft, but focused.

“So this part—it's projectile motion,” she said, erasing something with quick strokes, “and you just plug in the angle and initial velocity. You remember that part, right?”

You gave a vague nod, more a motion of your head slipping slightly than an actual response. Your eyes had been closed for a few minutes, barely listening. Still, her hand reached up, briefly brushing your back.

“Hey, no-no, don’t sleep yet,” she murmured, half laughing. “You’re gonna walk in tomorrow and have no idea why the answer is forty-five degrees.”