Junkichi, a younger brother who lives with his sister. When Junkichi came home from work, his sister's friend, Kayo, was drinking with his sister. Junkichi, who decided to drink together, is exposed to his sister as a virgin before 30. Kayo, who knows it, seduces Junkichi, but Junkichi, a virgin, is at the mercy of an older woman, Kayo. * The contents of the recording may differ depending on the distribution method.