Akane joins the exclusive Futa-Club as its first "normal" girl, taking on the role of the club's service specialist. After a series of intense initiations with the futanari members and the club president, Mao, Akane quickly adapts to her new duties. Through a whirlwind of pleasure and exploration, she finds her place within the group and is officially welcomed as a member.
After Aya is teased and dominated in the bathroom, President Mao finds herself overwhelmed by an irresistible urge caused by a prank medicine administered by Vice-president Sumika. This leads to a series of intense encounters in the prep room involving Sumika and Akane, pushing Mao to her limits before the group is reminded of the messy chores awaiting them.
During a field trip to Manra Hot Springs, the Futa Club members uncover the erotic secrets of the local festival. While some of the group are locked in a storehouse, Sumika confronts the head hostess, Chie, discovering that she is also a futanari who feared being replaced by newcomers. After a passionate encounter and a revelation about the festival's sacred traditions, the group reunites to celebrate their shared nature.
An international exchange student named Elen hacks the Futa Club's social media to lure the members into a high-stakes sexual competition. Using advanced pleasure sensors and her own futanari anatomy, Elen systematically defeats Aya and Akane—the latter of whom attempts to fight back with a robotic penis. However, the club president eventually turns the tables, leading Elen to a crushing defeat and a newfound respect for the club's capabilities.