The Fujita mother and daughter are an incredibly promiscuous pair. Whenever the daughter has time off, she brings her boyfriend home, and the mother sleeps with him. Furthermore, the mother, Keiko, uses her brother Haruo's house as a hotel, and the reason Haruo lets her use his room is because Keiko occasionally sleeps with him too. The daughter, on the other hand, is having an affair with her mother's new husband and is even having an affair with her tutor...