A PTA Mom (43) Who Relieves Her Frustration By Having A Secret One-hour Karaoke Affair Once A Week With Her Eldest Son's Young Homeroom Teacher, Mariko Furuto.

Mariko serves as a PTA officer at the junior high school her eldest son attends. One day, at the chairperson's suggestion, they decide to have an after-party for the school festival, including the homeroom teacher. They get lively at the first venue, an izakaya, then move to a karaoke bar for the second party. Amidst this, the sexually frustrated Mariko sets her sights on her son's homeroom teacher. Using her experience as an older woman and maternal instincts, she clings to him seductively. Before long, the two fall into an affair...