Dissatisfied with an ordinary high school life, Akane Niimura decides to join the Futa Club. The organization consists solely of futanari—well-developed women with male genitals. The club's members spend their free time pursuing a single activity: indulging in as much sexual pleasure with each other as possible.

However, there is a major problem with Akane—she is a regular girl! Therefore she can only be admitted to the club as a "service specialist." Despite ending up with the subservient role of being a sex toy for the other members, Niimura is content with her position and resolves to fully enjoy the club's exciting activities.

[Source: MyAnimeList]