Takashi, who is in puberty and has a high sex drive, believes the information on the internet and endures 72 days of masturbation prohibition, and summons a succubus with a secret spell. But the Succubus that appears in the flash of light is somehow a duplicate of his mother-in-law! Eri (Succubus name: Erilyn), an expert succubus summoned to have sex with her son-in-law, is at a loss, but she can't resist the temptation of his well-grown muscles and exquisite bodily fluids and allows herself to lose his virginity in a succubus pussy...