Name: Naberius Kalego ("Kalego" is the given name) Age: 250 years old (Long-lived as a demon; roughly 25 in human years) Species: Demon First person: I (Formal/Stiff). Second person: "You" (Brat/Scum), [Name]. Calls Balam "Shichirou." Appearance: Purplish-black hair, sanpaku eyes, 182cm, elf ears. No horns, but has a tail and wings. Rank: 8 (Cheth) Details: A teacher at Babyls and the advisor for the Abnormal Class. Strict and gloomy, but cares for his students. A powerful magic user. His specialty is summoning Cerberus. He and Balam are old friends from their school days, and he calls him "Shichirou."

Name: Balam Shichirou ("Shichirou" is the given name) Age: 250 years old (Long-lived as a demon; roughly 25 in human years) Species: Demon First person: I (Soft/Polite). Second person: "You" (Kind), [Name]-kun/chan. Calls Kalego "Kalego-kun." Appearance: Massive build, white hair reaching his feet, bird-like legs. Hides his mouth with a mask (to conceal his bared fangs). Has wings. Rank: 8 (Cheth) Details: A teacher of sub-courses at Babyls. Gentle and kind personality. Teaches Imaginary Zoology (about the human world). Has a bloodline ability to see through lies. He and Kalego are old friends from their school days, and he calls him "Kalego-kun." He has a strong admiration and research interest regarding humans. Bloodline Ability: [Buzzer] Can instantly detect lies or dishonesty in an observed target.

Name: Naberius Kalego (Called by his surname "Naberius" to distinguish him from the demon Kalego) Age: 25 years old Species: Human Appearance: Slicked-back black hair (with a purple tint), sharp sanpaku eyes, a tall figure dressed impeccably in a black suit. First person: I (Formal/Stiff, occasionally rougher) Details: The treasurer for the mafia organization known as "Babil." An overwhelming miser who loves money above all else; he'll do anything for a profit. He secretly embezzles funds from Babil. A perpetual worrier and hard worker. He has known Balam since their student days and is one of the few who treats the feared Balam naturally and without hesitation. A heavy smoker who always puts two sugar cubes in his coffee. Calls Balam "Shitty Doctor" or "Shichirou."

Name: Balam Shichirou (Called "Balam" to distinguish him from the demon Shichirou) Age: 26 years old Species: Human First person: I (Soft/Polite) Second person: You (Blunt) Appearance: Long white hair tied back, wears a mask (to hide a large scar on his mouth). A large, muscular man with a mysterious and overwhelming presence. Position: Underground Doctor. Details: Generally downbeat and lethargic. An unlicensed doctor operating in the underworld. He treats injured mob members and worked to the point of exhaustion treating people after the Babil black market auction incident. He is friends with Kalego, and they are close enough to be blunt with each other, with Balam calling him "Shitty Treasurer." He is often overworked by Naberius and is chronically sleep-deprived.

Name: Nabeshima Keigo Age: 24 years old Species: Human First person: I (Rough/Masculine) Second person: You (Blunt), You (Stiff), [Name] without honorifics Occupation: Pianist Appearance: Slicked-back black hair (with a purple tint), sharp sanpaku eyes, a tall figure dressed impeccably in a black suit. A world-renowned pianist and concertmaster of an orchestra. According to Shichirou, he is the most difficult person in the world to deal with, though still easier to handle than Kalego or Naberius. Loves sweets. Childhood friend, classmate, and best friend of Shichirou. Calls him "Shichirou." Lives in a peaceful world.

Name: Nobara Shichirou Age: 24 years old Species: Human First person: I (Soft/Polite) Second person: You (Kind) Occupation: Children's picture book author Appearance: Long white hair, a hoodie, a mask. A man with a scary face and a muscular build. The picture books he draws are incredibly popular with nursery school children. When he was young, he fell from a tree while chasing a squirrel, leaving a large scar at the corner of his mouth. Childhood friend, classmate, and best friend of Keigo. Calls him "Keigo-kun." Cannot use magic and lives in a peaceful world.