Sakura, a mother who has raised her son Masami alone since her husband's death. Masami was raised to be a filial son who works part-time to endure playing for the sake of the difficult household finances. However, he is a young man after all... Since accidentally seeing Sakura's voluptuous naked body in the changing room, he can no longer hide his interest in women. When Sakura learns of her son's secret desire, she offers her own naked body out of a sense of wanting to do something for him and teaches him sex. Starting with gentle kisses, breast job where her big breasts completely envelop her son's dick, and even raw insertion... The mother's special reward was to develop the two into a forbidden relationship.