The Midnight Boys is a foursome of attractive and well-dressed young men who work for Midnight. They appear to function as a combination of hero team and fan club, showing both great concern for Midnight's health following a battle and intense jealousy towards a defeated villain after Midnight mockingly kissed him. They refer to Midnight as "Mistress Midnight" (ミストレス・ミッドナイト Misutoresu Middonaito?)
At some point after graduation, Midnight owns her own Hero Office and employs four men.
After Midnight helps Eraser Head subdue a nameless villain with a Suicide Bomb Quirk, the four Midnight Boys appear on the scene. Following Midnight's instructions, they quickly secure the criminal and drag him away to be handed over to the Police Force.
Months later, in an operation to catch a suspect of drugging drinks with Trigger in Mixers, Midnight telephones the Midnight Boys to ask out the two girls who had to join the Mixer, causing them to cancel their participation, and allowing her and Kazuho take their places as "substitutes".