Masaya's childhood friend's mother, Yuko, was Masaya's first love. More than half of the reason why I still go to Shiraki's house often is to see Yuko. That's why Masaya could see the subtle changes in Yuko's girlfriend. She seems lonely lately... That day, Masaya witnesses Yuko masturbating. Masaya, who saw that appearance, strongly wished to comfort Yuko. Of course Yuko would refuse to have a relationship with her son's friends. So Masaya decided to voyeur masturbation and use it as blackmail material.
