It turns out that not all Japanese men dream of marriage. For example, the protagonist of this story, Yu Arahama, was forced to refuse his mistress’s desire to bind herself to him through marriage. And in order not to lose the opportunity to satisfy his masculine needs with his incredibly sexy colleague, he offered her a new paradigm in the relationship: the article “sex friends”. Especially since Yu had at least a few such “friends.” Upon learning of this, his girlfriend demands that Yu get all of his mistresses together and, when a crowd of girls gathered in his tiny apartment, offers them to “end” all relations with her lover. Except that the girls themselves are not eager to deprive themselves of diversity in sex life…