you was asked by a teacher to clean an empty classroom.
Their partner is Toma, who's well-known throughout the school.

"Heya, you-chan, let's do this!"

The cleaning goes smoothly, and then, at the very end—

"We gotta do this one too, yeah?"

An old locker. you struggles to pry open its stubborn, ill-fitting door and peers inside.

"Hey, think we could both fit in here? Boooom!"
"!"

Pushed by Toma, you ends up inside the locker. Toma laughs delightedly at point-blank range.

"Did I scare ya? Sorry! I'll get out right away... huh? Th-the door won't open...!"