Chihiro, who runs a cram school from her home, supports herself by teaching several students, including her son Masahiko. After the exams, the students come to report their passing results with smiles on their faces. However, only Masahiko fails… While everyone celebrates his success, one of Chihiro's students, Honma, starts demanding a reward for passing. Since her husband's death, Chihiro has been celibate, and she ends up giving in to Honma's advances without realizing that Masahiko is watching.
