Tatsuo Kazuki, a college student living alone in Tokyo, returns home to his mother Sakura Kazuki's house, which is undergoing renovations. His cousin Masaru Hoshi and Masaru's mother, Ayano Hoshi, have moved in temporarily. Upon his return, Tatsuo finds himself sexually aroused by his mother, and unable to suppress his desires, he repeatedly fantasizes about having sex with her—eventually imagining her receiving creampie after creampie. Meanwhile, Masaru has turned his own mother Ayano into his submissive lover, establishing a forbidden master-servant relationship. When Masaru witnesses Tatsuo's mother-son incest firsthand, the complex family dynamics and tangled relationships spiral into a shocking tale of taboo desire.