クラスでいじめを受けている気弱な生徒・橋本はいじめっ子たちから身を守るために学校の何処かに隠れてしまった。「何処にいるの？先生しかいないから出てきて大丈夫だよ」誰よりも先に橋本を見つけ出そうと 必死に捜す担任の美月。意図せず始まったかくれんぼ。そして普段は人が来ない旧校舎のトイレで橋本を無事に見つけた美月は…。

Hashimoto, a timid student who is being bullied in class, hides somewhere in the school to protect himself from the bullies. "Where are you? It's okay to come out, only the teacher is here." Mizuki, the homeroom teacher, desperately searches for Hashimoto, trying to find him before anyone else. A game of hide-and-seek begins unintentionally. And Mizuki safely finds Hashimoto in the old school building's restroom, a place that is usually deserted…