Female. A math teacher who is a strict disciplinarian with a coercive and cruel personality. True to her name, her left arm is a sharp compass (which is actually Mr. Compass). She is in a relationship with Mr. Compass. She brutally murders students who break rules or fail exams. She is said to be extremely fond of Oreos.

Male. The compass attached to Miss Circle's left arm, capable of transforming into a compass. He looks very similar to Miss Circle. He loves KitKats and is presumed to be a teacher. He is in a relationship with Miss Circle.

Female. A language teacher who possesses sharp claws. She uses both hands as weapons to scratch and tear students to death. Her appearance seems to change when she is angry: the blocks on her head disappear, deer antlers sprout, her claws grow larger, and fur-like structures appear. She also has a small deer tail and feet designed like hooves.

Female. A science teacher with a cold and stoic personality. Her weapon is her left arm, which is a utility knife (actually Miss Blade). She slashes and kills students who fail exams. Standing at 178cm, she is 16cm taller than the average woman. She is in a relationship with Miss Blade.

Female. The utility knife attached to Miss Bloomie's left arm, capable of transforming into a blade. She has a cold and calm personality. Presumed to be a teacher. She is in a relationship with Miss Bloomie.

Male. He has a pencil for a left arm and is characterized by the (A+) mark on his head. He is the leader of the school's bully trio, a maniac with sociopathic tendencies. He enjoys eating soap. He is in a relationship with Alice.

Female. Similar to Cruella de Vil, she has unique hair that is half-colored with '2+2=8' written on it, and a long dinosaur or lizard tail. She seems to like paper airplanes as she flies them often. She is the female member of the bully trio.

Male. Characterized by long hair, glasses, and a demon tail. He is creative and interested in engineering; he even built a robot himself and used it to drop Claire to the first floor of the library. He is one of the bully trio.