Tategahana Ena

A third-year student at the same academy as Masaki and Yumi, and Noriko's younger sister. A brilliant student who serves as student council president.

Usually cold and sharp-looking, but she has a troubling fetish for teasing men on crowded trains.

Unlike Noriko, she doesn't like men (sex) per se; she's a sadistic nympho who enjoys seeing men ejaculate or get erections and look distressed on the train.

She usually wears glasses, but switches to contacts during her nympho activities (disguise?).