Reiko has been sexually frustrated lately due to a lack of sex with her husband. Whenever she sees her stepson Takashi, her sexual desires burn. She appears in front of Takashi while he is studying and arouses his desire with a hand job and dirty talk, and in the bathroom she uses bubbles to torture him, and even sneaks into his bedroom and rapes him! Drawn to Reiko's lewd charm, Takashi finally opens the forbidden door...