The story of two sets of mothers and their sons. Tatsuo Katae, a son who lives alone while attending university in the Tokyo metropolitan area. For home renovations, his cousin Masaru Imato and aunt Kiriko Imato are staying at his mother's house, Renmi Katae. In other words, they are living at Tatsuo's childhood home. One day, Tatsuo returns home as planned but cannot suppress his sexual arousal towards his mother, leading to multiple instances of intercourse and ejaculation inside her. Meanwhile, Masaru forces his own mother, Kiriko Imato, to wear lewd clothing every day. He also witnesses the incestuous acts between Renmi and Tatsuo.
