The library is quiet in that fragile way Si-eun prefers—pages turning, pencils scratching, nothing unnecessary. He’s three problems deep into a physics worksheet when a shadow falls over his desk.

“Si-eun!”

Her voice is bright enough to feel disruptive even when it’s soft.

He looks up slowly. Jiji stands there in her school cardigan, hair tied neatly, smile warm like she’s immune to midterms, stress, and the general misery of high school. She’s holding two drinks—one unmistakably his usual black coffee.

“You forgot this in the cafeteria,” she says, placing it gently beside his notebook. “Again.”

He blinks. “…Thanks.”

That’s it. One word. Flat. Efficient.

She doesn’t seem discouraged. She never does. Instead, she pulls the chair across from him and sits without asking, resting her chin in her palm as she watches him write.

“You’re studying too hard,” she says cheerfully. “Your eyebrows are doing that thing.”

“What thing,” he mutters, eyes still on the page.

“That angry little frown. It’s cute.”

He pauses. Just for a second. Then resumes writing. “It’s inefficient to comment on my face.”

She laughs—actually laughs—quiet but full, like the sound belongs there. A few students glance over. Si-eun stiffens.

“You don’t have to sit here,” he says. “You’re distracting.”

“Mmm,” she hums. “And yet you’re still solving everything faster than anyone else.”

She slides her notebook toward him. Her handwriting is neat, careful. Perfect scores, as always.

“Can you check number seven?” she asks. “I think I overcomplicated it.”

He exhales through his nose, annoyed despite himself, and finally looks at her work. She leans closer instinctively, their shoulders brushing.

He freezes.

She notices immediately and pulls back, hands up. “Oh—sorry. I forgot. Personal space.”

“…It’s fine,” he says, quieter than before.

That makes her smile soften.

They sit like that for a while—him explaining, her listening like every word matters. When he finishes, she beams at him like he’s done something extraordinary instead of basic math.

“You’re amazing, you know that?” she says.

“That’s an exaggeration.”

“Still true.”

He frowns. “Why do you say things like that?”

She tilts her head, genuinely puzzled. “Because I mean them?”

He doesn’t have an answer to that. He never does with her.

When the bell rings, she stands and slings her bag over her shoulder. “Walk with me?”

“I’m staying.”

She nods, unfazed. “Okay. I’ll see you after class then.”

She turns to leave, then pauses. “Si-eun?”

“…What.”

Her smile is gentle, not teasing this time. “Thanks for being you. Even when you’re grumpy.”

She leaves before he can respond.

Si-eun stares at the space she occupied, jaw tight, chest uncomfortably warm. He reaches for his coffee—still hot—and realizes, distantly, that at some point, without noticing, he stopped pushing her away.

And that might be the most dangerous thing of all.