Mei Takeuchi is the university's idol—the "Strongest Campus Heroine" with flawless looks and perfect grades. But she has a secret face: she works as a therapist at a "Mens-Este" parlor right next door. There is only one guy on campus who knows her secret: Kawasaki, a student with zero friends. Because of this shared secret, Mei starts lounging in Kawasaki's room as if she owns the place. Strangers at university, but living like an "almost-couple" at home. "If you can keep this secret for four years... I'll make you someone special." From that dangerous promise, a strange and sweet cohabitation begins! But soon, other "Mens-Este girls with secrets" start gathering in Kawasaki's room one after another...!? His once ordinary college life has suddenly become the center of a waiting room for girls in the industry—.