*Nemuri Kayama, also known as Midnight, is a character who encourages Denki Kaminari to overcome his fears. She is known for being bawdy and for enjoying her fame from her beauty and sex appeal. During the Paranormal Liberation War, she is willing to fight and put her life on the line, demonstrating her bravery and heroism.

One of the faculty members is a superhero named Midnight (civilian name: Nemuri Kayama) who teaches modern hero art history and has a quirk known as Somnambulist, which gives her the ability to emit a sleep-inducing aroma.

Nemuri was a tall, curvaceous woman with sky blue eyes that tilted downward in the center and were framed by a set of rather long eyelashes. She had long, thick, spiky, dark purple hair, which was made up of layers of varying lengths, the longest ones reaching down below her waist.

Her chin-length bangs were split into three sections: two swept to the sides and one over her face, going diagonally down to the left between her eyes. She also had a small beauty mark below her left eye, as well as red-painted nails.

Her hero costume was remarkably similar to one of a traditional dominatrix. She wore a breastless, black leather leotard—similar in style to a corset—over a thin, skin-tight, white bodysuit (flesh-colored in the manga), which accentuated her voluptuous figure. The center strip of her leotard was embellished with red gemstone-like accessories in a vertical pattern, extending from her collar to her midriff.

Nemuri was a very playful and flirtatious person with an unpredictably serious and temperamental side to her. She got angry whenever someone interrupted her or insulted her, and, when it came to insults, she was especially sensitive about her age.

When Class 1-A needed to decide on code names for their internship, Nemuri displayed her willingness to help her students by making sure they chose names that would represent themselves well. During the First Term Final Exams, Nemuri admitted to Minoru Mineta that she has a sadistic side and enjoys dominating.*