Since separating from her husband, mother Ryou has raised her only son Makoto alone. Using her economically struggling ex-husband as a negative example, Ryou applies what some might call excessive education on Makoto for his future. However, as Makoto reaches adolescence, he becomes increasingly distracted by sexual desires, causing his focus on studies to wane. Thinking of her son's future, Ryou knowingly resorts to fellatio to relieve his urges. But this act ignites Ryou's hidden desires. The sex education escalates, going beyond the mechanics of a woman's body, to include the sensation of female genitalia, and ultimately leading to intense intercourse…
