Seigo, a son, is reminded of his first love when his mother's friend Ayumi returns to their hometown for the first time in 10 years. That night, Ayumi, drunk and in a good mood, invites him to kiss her... Seigo is hesitant at first, but is excited by her bold behavior. When he decides to sneak a peek into the bathroom, he witnesses Ayumi masturbating. Seigo hurriedly runs away from the scene, but Ayumi notices him and visits his room in the middle of the night...