Nanako lives with her son. One day, Nanako is forced into a relationship by a man and reluctantly gives in. During the act, her son returns home and is shocked to see his mother's figure. The son tells Nanako that he got an erection from watching sex and asks her to teach him about a woman's body as well. Despite being at her wits' end, Nanako decides to accept her son as part of sex education…
