The story of two sets of mothers and sons. Tatsuo Hagak, a nephew who lives alone while attending a university in the Tokyo metropolitan area, for home renovation purposes, his cousin Yasuhiro Sawamura and mother Reiko Sawamura are staying at the house of his aunt Sorami Hagaka, that is, Tatsuo's real home. One day, Tatsuo returned home but could not suppress his sexual excitement towards his own beautiful-assed mother, and after several obscene fantasies, he ended up having sex with her multiple times. Around the same time, Yasuhiro also had sex with his own mother. The two sons, who saw each other's mother-son incest, decided to execute a certain obscene plan...
