Takashi, a virgin, heard from his friend that women also have sexual desires and masturbate. Out of curiosity, he forced his sister, Mimi, to drink a large amount of aphrodisiac. Initially, as planned, he succeeded in watching Mimi's masturbation after she became aroused. However, due to the overpowering effect of the drug, Takashi was discovered by Mimi who had lost control and grabbed his penis, taking his virginity. Afterwards, until the drug wore off, with no escape in their home as both parents were out, he was repeatedly assaulted by Mimi, now a nymphomaniac, who drained him of every last drop of semen…
