A mother, Ryoko, worries about her shy only son. One day, she finds sticky stains on her son's underwear and discovers her own underwear in his room. Realizing that her son is struggling with sexual issues, Ryoko decides to educate him using her own body. However, the son becomes captivated by his mother's mature yet beautiful body. He attacks his mother while she is secretly masturbating and forcefully penetrates her vagina, but Ryoko happily accepts her son's growth.
