Nanako husband is an obstetrician-gynecologist, has a problem. Her only son, Takashi, has become a recluse and stopped going to school. One day, Takashi tells Nanako that he wants to become an obstetrician-gynecologist like his father and that he will go to school again. Nanako is happy, but the next day he comes home with a bruise on his face. She tells him that he was mocked for wanting to become an obstetrician-gynecologist and not knowing much about sex. Takashi says he won't go to school again. Nanako decides to use her own body to start teaching sex education, but...