; : :The titular Miss Kuroitsu, an assistant for the evil secret society Agastia's Monster Development Department, who finds herself forced to balance the outrageous and sometimes contradictory demands of her superiors as she tries to create monsters to fight against Agastia's enemies. ; : :Kuroitsu's superior, an intelligent professor who usually wears a high-tech visor over his eyes. However, his laid-back demeanor often interferes with his work, forcing Kuroitsu to fix issues that arise. It is later revealed that Hajime is the older brother of Kenji, but neither one knows about the other's secret identity. ; : :A wolfman whose body was abruptly changed to a feminine form before completion after Akashic demanded Bete be "cuter". Bete still
identifies as male despite the confusion this causes with coworkers. After surviving his initial battle with Blader, Bete was transferred into the Monster Development Department as another assistant. ; : :The Chief of Staff for Agastia whose menacing appearance hides a pragmatic temperament. He often works overtime to keep Agastia running smoothly, and is not afraid to go against Akashic when necessary. ; : :The leader of Agastia, a small girl with a flighty personality who secretly wields immense strength. ; : :A 22-year-old
convenience store worker who is secretly the superhero Divine Swordsman Blader that Agastia is fighting against. He has a crush on Kuroitsu, as she is a frequent guest at his shop, but is unaware of her real job. Later revealed to be the younger brother of Doctor Sadamaki, but neither sibling is aware of the other's secret identity. ; : :A seemingly-immortal vampire lady known as the "Pluripotent Cellular Executive" of Agastia. She takes pride in her work and ability to audit the departments underneath her. Outside of work, she is a secretly a big fan of a certain idol group. ; : :One half of the licensed Magical Girls: Pilia Magia duo. An incredibly short-tempered middle-school girl. ; / : :One half of the licensed
Magical Girls: Pilia Magia duo. A taller boy who is Reo's classmate, his Magical Girl body is that of a slightly shorter girl but with larger breasts than Reo, making her jealous. ; : (English) :Sadamaki's former classmate who runs the Monster Development Department for Black Lore. ; : :Hoen's assistant who enjoys teasing Wolf Bete whenever they meet. ; : :A monster composed of homemade chocolate in hopes of creating a Valentine's Day themed monster to fight Blader, but was abruptly cancelled when her source material was subject to a
recall. However, the Monster Development Department kept Melty's design and brings her out on various occasions. ; : :A middle-manager working for Black Lore, carrying out his leader's wishes. After being hit by Bull Head's psychic attack, he immediately quit the company. ; : :The leader of the evil organization Black Lore ==Media==