The film is about a mother who often sees her beloved son acting strangely at home, such as staying in the toilet for a long time, secretly masturbating with her mother's underwear. This makes Reiko Sawamura feel worried, so she confides in her husband, but he doesn't care much and tells her to talk to her son herself to find out what difficulties he's having. That night, Reiko accidentally sees her son secretly reading hentai, which makes her very surprised about this, so at that moment she thinks that she will definitely teach a lesson. Sex education to her son.