A mathematics teacher. She has white skin, black clothes, and very long, messy black spiky hair with two horns resembling cat ears on top of her head. Using a giant compass on her upper right arm as a weapon, she is a cruel and terrifying psychopathic teacher who mercilessly slaughters students who fail their tests. She loves Oreos. Female.

A language (Language Arts/English) teacher. She wears "A, B, C" letter blocks on her head and two feathers on each side, dressed in white. She is a cruel teacher who mercilessly slaughters students who fail their tests with her giant claws. When angered, she transforms into a terrifying form with deer-like antlers. Female.

A science teacher. She wears black clothes and is characterized by her right arm, which is transformed into a sharp cutter. Like the other killer teachers, she is cold-blooded. She mercilessly slaughters students who fail their tests. She is short in stature and a very psychotic teacher. Female.

A music teacher. He has a kind and cowardly personality and does not attack students. He is always breaking out in a cold sweat and acting timid. He has shoulder-length white bobbed hair, with the left side of his bangs featuring a piano key pattern. He has two white pencils and small black horns on his head. Like the art teacher Miss Sasha, he is a moderate. He is liked by Miss Sasha. Male.

A history teacher. She is calm and does not panic even when incidents occur. She is the only one with dark skin and wears her black afro hair in pigtails. She is characterized by two horns on her head and square glasses. She wears a white blouse and a black skirt. Female.

An art teacher. She is a kind and gentle teacher who does not attack students. She is very caring and has a friendly personality, being well-versed in handling small children and students. She has messy black hair in a ponytail, wears a maroon beret, and one side of her face is hidden by a green book. Like the music teacher Mister Demi, she is a moderate. She has feelings for Mister Demi. Female.

The principal. She has a messy white ponytail and two hairpins in her right bangs. She has two black horns on her head, and the left one is broken. A piece of paper with a mysterious triangular symbol is attached to her right horn. She wears a monocle on one side of her face. She wears a green suit jacket, a white shirt, a black tie, and a long black skirt. She is strict and dignified, overseeing the killer teachers like Miss Circle. She remains unfazed even when students are slaughtered. She is the absolute ruler of the school with a cold-blooded nature. Female.

The most dangerous student, isolated within the school (the main antagonist). She is extremely violent and mercilessly slaughters anyone who wanders into "Alice's Room" deep inside the school. In her human form, she has messy brown hair with a small tiara, but when she reveals her true nature, she transforms into a giant, demonic monster with sharp claws and two long horns. She is the girlfriend of Oliver, the leader of the bullies. Despite her cruelty, she never uses violence against Oliver and treats him very kindly.