Aya Masuo is a married woman with a serious doctor husband named Kenji and a son, Akihiko, who attends a cram school. However, Akihiko fails to focus on his university entrance exam studies, and his grades continue to decline. Kenji blames Aya for their son's apathy, believing it stems from her bloodline, and repeatedly rejects her sexually. One day, Aya is shocked to discover that an investment she secretly made has crashed, wiping out their fortune. Learning of this, Akihiko—already harboring deep, repressed feelings for his mother—becomes emotionally twisted. Gradually, he descends into darkness, raping Aya and turning her into his personal sex slave, fulfilling his depraved desire to sexually dominate her.