The story of two sets of mothers and sons. Tatsuo Kondou, a son who lives alone while attending university in the Tokyo metropolitan area. For home renovations, his cousin Yasuhiro Yabe and aunt Suee Yabe are staying at his mother Yukimi Kondou's house—essentially, Tatsuo's childhood home. One day, Tatsuo returns to his hometown with his girlfriend but cannot contain his sexual excitement towards his mother, repeatedly having sex with her while leaving his girlfriend aside. Around the same time, Yasuhiro also has sex with his own mother. The two sons, having witnessed each other's incestuous acts, decide to execute a certain lewd plan…
