Etsuko Takayanagi embodies the duality of a model student and concealed transgressor. Publicly, she garners admiration as a high-achieving tennis star and student council president, crowned with the ironic nickname "Eternal Virgin" for her chaste reputation. Privately, she trades sexual favors with authority figures, including a teacher, to secure academic success. In the anime, her life intertwines with Hanappe Yamada, who harbors an obsessive infatuation, secretly photographing her during vulnerable moments. When targeted by demons exploiting her secrets, her illicit affairs unravel, culminating in a violent alleyway confrontation where Hanappe’s powers unleash her repressed desires, leading to her temporary demise and ambiguous hints of resurrection.

The manga delves deeper into her calculated persona, depicting a tense train encounter where Hanappe resists using his abilities publicly, instead manipulating her into an abandoned bowling alley. There, she confesses her extensive sexual history, engaging him in a charged encounter abruptly halted by a fatal helicopter crash. Her arc juxtaposes societal hypocrisy against personal vulnerability, revealing fleeting empathy toward Hanappe during his bullying, yet prioritizing self-preservation over redemption. Her demise, marked by chaos and interrupted revelations, underscores the fragility of façades in the face of truth.