Yukako's son Takashi was a rōnin. One evening, Yukako took a late-night snack to Takashi's room while he was studying and found an erotic book underneath his reference books. It was an erotic book featuring women of the same age as Yukako. Yukako thought that Takashi should not be interested in older women any further, so she stripped naked herself and showed him masturbation, making Takashi masturbate as well.
