On the first day of a long holiday, Negishi stays over at his friend Yoshio's house. Yoshio's mother, Tsubasa, greets him, and her beautiful appearance and subtly seductive figure leave Negishi mesmerized. That night, while heading to the bathroom before bed, Negishi catches Tsubasa having phone sex with her lover. Overcome with arousal, Negishi promises to keep it a secret from Yoshio and begins caressing Tsubasa's heated body. His youthful desire spirals out of control, driving him to the extreme act of forcing her to call her lover mid-sex.