Yu and Shin'ya are a loving couple. However, Shin'ya's erection is bad, perhaps due to his age. Fearing disappointment, Shin'ya decides to rely on a powerful aphrodisiac, but Yu and her son Hayato accidentally drink the aphrodisiac-laced drink. The two of them crave each other so deeply that their reason and consciousness fly away with the sudden surge of lust. Even after realizing that the aphrodisiac was the cause, their bodies, which have come to know overwhelming pleasure, cannot forget the stimulation…