When Shinya was a child, he lost his brother's gameboy while playing in the park. A girl named Akane discovered it, as it had the name Shego (Shinya's brother) written on it. Shinya introduced himself as Chego so she wouldn't have to ask Akane any questions. Later, while walking in the park, Akane confesses to Shinya that she is sick, and it really bothers her that no one will marry her even when she is cured. Shinya reassures the girl and tells her that he will definitely marry her when they grow up. A few years later, Schego brings his bride to the house. As it turns out - it is the same girl Akane, who still thinks that it was Shego who promised to marry her. However, the older brother's wife Sayumi is aware of this confusion. She summons Shinya for a talk, where she asks him if he intends to fulfill the promise he made to Akane several years ago. When he answers in the affirmative, she explains to Shinya that Akane is inexperienced in lovemaking and Shinya should help her relax and get the most out of it. Shinya, in turn, admits to Sayumi that he himself is a virgin. Then, Sayumi decides to teach the boy the art of lovemaking. After school, Shinya stays for "extra lessons" with Sayumi. After completing the first course on how to please a girl, Shinya goes home. That same night, the boy goes to Akane's room to show him everything Sayumi taught him.