Nemuri Kayama

Midnight, the +18 only Heroine is a Pro hero and staff at Yuuei. She was the Chief Referee of the Sports Festival for year 1.

Ultimate Space & Jams Arc
Midnight appeared along with the other Pro heroes when Class 1-A was attacked by the Villain Alliance.

Sports Festival Arc
At the beginning she tells everyone to play fair during the Sports Festival. The students question her "+18 only" tagline, and ask if its ok even though this is a high school. She yells at them and tells them to silence. She then calls Katsuki Bakugou, the player rep for the Freshman up to the stage.