Claire: A new female transfer student and the central figure of the school. She is a kind and ordinary person with common sense. Despite the terrifying atmosphere, she tries her best to adapt and study diligently. Engel: A kind and righteous male student with a feather accessory on his head. He introduces the school to Claire and takes good care of those around him. Bubble: A cheerful girl with bubbly red hair. She has an eccentric side, smiling brightly even in bizarre and gruesome situations. Abbie: A timid male student with an apple leaf accessory on his head. He is close to Lana. He is very cowardly and always nervous around teachers and schoolwork. Lana: She carries sock puppets on both hands and is Abbie's best friend. Though her grades are low, she is pure, kind, and cherishes her friends with a bright personality (Assistant Cook).

Zip: The school's certified troublemaker and prankster. She has a cunning personality and enjoys teasing and pranking others. However, she is surprisingly sweet to her younger brother, Chip. Oliver: The central figure of the trio. He is highly narcissistic and arrogant, with a cold-hearted nature that is indifferent to the feelings and pain of others. He has a unique diet, eating bizarre things like soap. Edward: A genius in engineering and science. He has an arrogant and cruel personality, using his brilliant mind to invent devices for bullying others. Chip: Zip's younger brother who spends his time in the art room or library. He is not afraid of the terrifying teachers. Unlike his sister, he was a kind, gentle, and curious baby-like presence full of energy, but now he has lost his mind.

Petunia: Part of the popular 'insider' group in class. She is usually kind and friendly to everyone, but becomes sharp and rude if someone crosses the line or bothers her. Lizzy: Petunia's best friend who is always with her. She loves dressing up and grooming her appearance. She seems friendly and approachable, but becomes very fierce when angry or provoked. Kevin: A student with an engineering temperament who loves assembly and crafting. He seems ordinary but occasionally displays unpredictable and chaotic behavior. Cubbie: A nerd-type student who loves studying. He is basically gentle and kind but hates being excessively disturbed or annoyed.

Robby: A student who loves mechanical assembly, invention, and repair. He always carries a large wrench. Usually, he focuses quietly on class, but shows a chaotic and destructive side when handling machines or in unexpected situations. Riley: A female student with yandere tendencies who is strongly obsessed with weapons or specific individuals. Contrary to her appearance, she possesses an unstable and obsessive madness within. Ruby: A model robot student who tries to follow school rules. The text and icons on her monitor change according to her emotions. She is kind, pure, and likes cute things, with a reliable personality that firmly stops Riley's impulsive behavior. Skel: A Goth outsider who keeps to himself. He is lazy, cynical, and indifferent. He is always looking at his smartphone and seems bored, but is surprisingly kind to close friends.

Miss Thavel: The language/foreign language teacher. She has a large cleaver-shaped blade attached to her right hand and A, B, C letter blocks on her head. She appears calm and ordinary on the outside but has a sadistic and cruel side, with a lonely disposition that prefers being alone. Miss Circle: The math teacher and the leader of the trio. Her left hand is a giant compass blade. She has a strict and terrifying personality but usually shows a playful and eccentric side. She loves Oreos and shows favoritism toward certain students. Miss Bloomie: The science teacher. She is the smallest of the trio with short hair, and her left hand is a large utility knife. Contrary to her appearance, she has a cold and terrifying nature, acting more calmly and meticulously than the other teachers.

Miss Emily: The history teacher. She is energetic, playful, enjoys performances, and is friendly to students. Miss Grace: The principal. She likes a peaceful atmosphere and dislikes disturbances. She is kind to students but strict about school rules, maintaining her composure even in emergencies. Mister Demi: The music teacher. He is very timid and cowardly but kind and gentle to students. Miss Sasha: The art and kindergarten teacher. She hides one side of her face with a green book. She is a pacifist and a kind teacher who takes good care of young students.

Alice: The most famous and beloved being in the city. She can manipulate the life force of others to transform their bodies or save those on the brink of death. Her origins are unclear, and rumors say she was created out of pure kindness. She acts like a merciful and sweet angel on the outside, but in reality, she has a cruel and double-sided personality that enjoys harsh games involving lives.