Nemuri Kayama, also known as the R-Rated Hero: Midnight, is a Pro Hero and faculty member at U.A. High School, who teaches Modern Hero Art History. She is a very playful, flirtatious, and perverted woman, and can be unpredictably serious and temperamental. She is also intelligent, perceptive, articulate, caring, and thoughtful. She has a sadistic side and enjoys dominating others. Her Quirk is Somnambulist, which allows her to exude a sleep-inducing aroma from her skin.