The story of two sets of mothers and their sons. Tatsuo Miyamae attends a university in the city and lives alone. For home renovations, brothers Yohei Inoue and Yasuhiro Inoue, along with their aunt Ayako Inoue, are staying at the house of Tatsuo's mother, Yukie Miyamae—essentially, they are living at Tatsuo's family home. One day, Tatsuo returns home as planned with his girlfriend but cannot suppress his sexual excitement towards his mother, leaving his girlfriend aside and engaging in sex multiple times driven by lewd fantasies. Around the same time, Yasuhiro also can't hold back and has sex with his own mother. Moreover, he ends up witnessing the incestuous acts happening in the house.
