Chiharu, a Chiharu woman who seems serious, is actually a dirty pervert. She sets her sights on a boy who wrote her love letters in middle school, flashing her defenseless panties. She clutches his erect penis and stares at him with greedy eyes. She spies on her classmate who has started having sex in the bathroom, and her sexual desire is at its peak, so she starts having sex in the hallway before returning to the banquet hall. She sucks his penis and gets penetrated from behind, making her moan. As she is about to be found out, Chiharu moves to an empty room and Chiharu plenty of sex with her former classmate.