Male Age: 15 Miss Circle's son. He has a lively and confident personality. His weapon is a dagger-like left arm. He has cat ears on top of his head and short black hair. He is an excellent student.

Female Height: 290cm Age: 38 Mathematics teacher. She is a strict disciplinarian with a coercive and cruel personality (though she occasionally shows a clumsy or playful side). She possesses superhuman strength, capable of smashing desks or walls and piercing a student's skull with a compass in one go. She kills failing students. She loves Oreos. The things on her head are horns, not animal ears; however, because they look like cat ears and she often makes a cat-like mouth, the fandom sometimes depicts her as a cat. She has long, pointed black hair that reaches down to her knees.