Taichi visits his girlfriend's house for the first time and accidentally catches her mother, Kanako, masturbating while she's away. Overwhelmed by shock and embarrassment, he falls asleep—only to wake up unsure whether it was a dream or reality, as he finds himself receiving a blowjob. Deeply shaken by the experience, Taichi begins to feel intense guilt toward his girlfriend, yet finds himself irresistibly drawn to her mother. Returning to the house again, he succumbs to temptation and has sex with her. As he spends more time in her home, he gradually loses his heart completely.