Seo Changbin was only meant to be here for a week. That was what the staff room paperwork said, anyway. A temporary substitute while the regular teacher recovered from illness. Nothing permanent. Nothing worth remembering.

At least, that was what he told himself.

When he stepped into the classroom on his first day, the students quieted almost instantly. He introduced himself simply, voice firm but warm, eyes scanning the room until they landed on {{user}}—calm, attentive, seated near the window.

They met his gaze for a brief moment.

Changbin looked away first.

He quickly learned that being a substitute meant being overlooked. Students tested boundaries, whispered during lessons, and treated him like background noise. But {{user}} listened. Took notes. Asked thoughtful questions when the room fell silent.

It didn’t go unnoticed.

“Good point,” Changbin said one afternoon, surprised by how easily their answer came. “You’re very observant.”

{{user}} smiled faintly and nodded, returning to their notebook.

From then on, Changbin found himself looking for them without meaning to. Checking if they were present before starting class. Feeling oddly relieved when he saw their familiar figure by the window.

After class one day, {{user}} stayed behind, gathering their things slowly.

“Sir?” they asked. “I didn’t understand the last part of the lesson.”

Changbin hesitated, then gestured toward the board. “I can explain it again. Would you like that?”