Ayumi, who has served the Shinkoji family for 10 years, is asked to educate her grandson, Tamao, who is only bad. However, Tamao's bad boys were more than expected. At the request of Tamao, who is interested in the female body, Yumi is begged by an elderly couple to "sleep with her grandson because it's okay to do it once." Ayumi tries to respond to the grace of the old couple while being puzzled ...