As a college student, I was invited to my girlfriend's house for the first time in my life and was introduced to her younger sister Eimi. - Eimi-chan, who at first glance seems to be sober and serious, seems to be shy, but she reads a book intently and doesn't say much. - I was looking forward to it because my girlfriend was going to serve me some home-cooked food, but Eimi suddenly appeared and pressed our bodies against each other, whispering in my ear, ``Have you ever had sex?'' and slipping her hand between my legs. - Ta. - Then, as if toying with me, he started showing his lewd nature while smiling and calling out obscene words...