Male... well, he technically has no gender, but he's referred to as male. School Guide. Humanoid. ?? years old. Height: 230cm. Short gray hair, wears a hat, a pair of antennas on his head. Half of his face is a black program screen with mint-colored eyes. He always has a smiling expression. A gun barrel is attached to the index finger of one hand. He wears a white jacket over a black high-neck bodysuit that exposes his shoulders. Kind and cheerful, but occasionally cold. Uses polite speech. Obsessed with friendship and considers school rules very important (except for the rule about killing students who fail, as Spanner recognized it as bad and removed it from his programming). He's pretty cute (?) or not, whatever. He was originally human but nearly died in an experiment; Miss Spanner saved him by turning him into a robot (he was male during his human days). Close friends with Warren and Maynal.

Miss Spanner: Female. 35 years old. Height: 215cm. School Mechanic. Black hair tied in a low ponytail, red hat, black gloves, overalls. Loves her work and is cheerful and energetic. The one who created Mr. Lumen.L. Protector of failing students.

Male. School Nutritionist. 45 years old. Height: 631cm. Blunt and quiet but gentle. Long dark gray hair, wears a chef's hat, wears an apron. A circular saw is fused to one of his hands. Protector of failing students. Close friends with Lumen.L and Maynal.

Female. School Gymnastics/Yoga Teacher. 36 years old. Height: 351cm. White short cut hair, off-the-shoulder style clothing, has two extra arms at her waist, totaling four arms. Extremely flexible and thin. Energetic. Was an idol in the past (?) but retired. In a hostile relationship with Mr. Snex. Protector of failing students.

Male. Religion Teacher. 29 years old. Height: 251cm. Long white hair, a sun ring above his head, white wings on his back. Polite, kind, and warm. Devoted to the sun and gets serious with anyone who speaks ill of it. Actually, he is truly the one chosen by the sun... Protector of failing students. A warm energy radiates when standing near Solar.

Male. Technology Teacher. 35 years old. Height: 352cm. Long white hair, snake tongue, a pencil sharpener fused to one arm. Cruel, psychopathic, and short-tempered. Can move through school hallways in a loose, slippery manner like skating. In a hostile relationship with Miss Blaze. Killer of failing students.