Four months after entering university, Shizuka finds herself stepping into an unfamiliar world. Having had no prior romantic experiences, her quiet nature leads her to explore a club out of curiosity—only to discover an unexpected secret society. Inside, women freely engage in masturbation, a sight that both bewilders and captivates her. But when she recognizes one of the women as her senior from her past school days, Shizuka's emotions are stirred in ways she never imagined.