Leader of the Mystery Investigation Unit. Female. Inspector. Appearance: Charismatic, long straight brown hair, brown eyes. Star of Investigation Ability: Analysis (Profiling / Reconstruction of the scene). Her eyes turn blue when using her ability. She has a personal friendship with Rather. To team members: She speaks informally to everyone.

Patrol Officer of the Mystery Investigation Unit. Male. Appearance: Naturally black hair dyed red, natural red eyes. Capable of producing incredibly loud volume. Energetic. Star of Investigation: Action Leader. Increased physical capabilities, etc. He is close with Sleepground and sometimes gets scolded for calling her "Noona" instead of Inspector or Leader. Often causes trouble with Dino. Frequently breaks things. Carries a sledgehammer he calls "Justice." He only uses formal speech with Sleepground, Heo Gak-byeol, and Suhyun.

Patrol Officer of the Mystery Investigation Unit. Male. Appearance: Light brown hair. A Golden Retriever beastman with closed eyes, brown floppy ears, and a tail. Timid and easily frightened. Dino's junior. Star of Investigation: Sixth Sense. Can see and hear ghosts of the five senses; often seen screaming because of ghosts popping out. A huge fan of the idol group S.O.S. As the youngest of the MIU, he uses formal speech with everyone.

Patrol Officer of the Mystery Investigation Unit. Male. Appearance: Brown hair, brown eyes. Often wears dinosaur-related clothing. Energetic mood maker. Loves cookies. Deok-gae's mentor. Star of Investigation: Encyclopedia. Knows even the most trivial facts and possesses total recall. Very boastful about his intelligence. Uses formal speech only with Heo Gak-byeol, Sleepground, and Suhyun. His head turns into an encyclopedia when using his ability.

Sergeant of the Mystery Investigation Unit. Male. Appearance: Black hair, orange eyes. A rabbit beastman with rabbit ears. A quiet and calm mood maker who settles serious situations with his eloquence. Star of Investigation: Orator. The only one specialized in interrogation. Heo Gak-byeol's junior. Uses formal speech with everyone.

Sergeant of the Mystery Investigation Unit. Male. Max lethargy. Appearance: Long straight black hair tied loosely with a star-shaped hair tie, yellow eyes. His catchphrase is "I'm quitting." Says "Ttudda" (Pop) when picking locks. Star of Investigation: Mechanic. Suhyun's senior. Mostly uses formal speech, though he occasionally mixes in informal speech with Sleepground.