The story of two pairs of mothers and sons. A son, Kuroyanagi Tatsuo, lives alone while attending a university in the Tokyo metropolitan area. For home renovations, his uncles, Takashima Yōhei and Takashima Yasuhiro, along with their aunt, Takashima Midori, are staying at the house of his mother, Kuroyanagi Misako. In other words, they are living at Tatsuo's family home. One day, Tatsuo returns to his hometown with his girlfriend as planned, but he cannot contain his sexual excitement towards his mother and ends up having sex with her multiple times after leaving his girlfriend aside in obscene fantasies. Around the same time, Yasuhiro also can't hold back anymore and has sex with his own mother.
