Yuri, the close friend of his mother who left home due to her husband's infidelity, begins staying at the house for a while. Her sexy, mature figure is far beyond what one would expect from his mother's classmate, making Satoshi's heart race. His attraction toward her grows stronger each day, and one day, he can't help but peek at her naked body while she's changing in the bathroom. This impulsive act drastically changes the course of their relationship. Back in his room, Satoshi begins masturbating, consumed by thoughts of her voluptuous, seductive body—only to be caught by Yuri herself. This moment sparks a new connection between them, unraveling a story of tangled emotions and awakening desires.