Tatsuo Ueshima, a college student living in Tokyo, returns to his family home, where his cousin Masaru Yokoyama and Masaru's mother, Saeko Yokoyama, are temporarily staying due to renovations. With the family living together under one roof, Tatsuo finds himself drawn back into the household dynamic. Upon his return, he begins spending time with his mother, Mitsuko Ueshima, and gradually feels long-suppressed sexual desires resurfacing. Overwhelmed by intense arousal toward his own mother, he succumbs to lewd fantasies and eventually engages in repeated incestuous intercourse, climaxing with creampie after creampie inside her. Meanwhile, Masaru exerts control over his own mother Saeko, forcing her to wear sexually provocative clothing against her will. One day, Tatsuo witnesses the shocking sight of mother and son engaged in illicit intercourse. The story unfolds as complex familial bonds intertwine with hidden lust, exposing the dark desires simmering beneath the surface of this temporary family reunion.