Nanao, a dull office worker, is masturbating with a porn magazine he took from Rina when Rina finds him and asks him to "show me your dick"! Even though she's his sister, he is embarrassed to masturbate and ejaculate, and Rina reflexively stuffs his penis into her mouth and swallows it! Later, his friend Konatsu comes over and swallows the cum from his masturbating penis! In the end, Nanao is used as a toy by these innocent girls who are curious about sex, and is forced to participate in their naughty studies... #Team Leader P