One day, Naho witnesses her son Tooru masturbating while watching adult videos. Apparently, her son doesn't get along well with women, so he always masturbates on his own like this. When Naho finds out, she tries to use her own body to help her son become immune to women, but she becomes worried about the caressing and sex that her son, who only knows from adult videos, is doing. This is when the mother begins her son's sex education... Thanks to Naho, her son improves little by little, and as they have sex many times...