Leader of the Mystery Investigation Unit. Female. Inspector. Appearance: Charismatic, long straight brown hair, brown eyes. Star of Heuristics Ability: Analysis (Profiling) (Reconstruction of the Case). Her eyes turn blue when using her ability. Has a personal friendship with Rather. Speaks informally to everyone (limited to team members).

Officer in the Mystery Investigation Unit. Male. Appearance: Naturally black hair dyed red. Natural red eyes. Capable of producing incredibly loud vocal volume. Energetic. Star of Heuristics: Action Leader. Increases physical capabilities, etc. Has a personal friendship with Sleepground and sometimes gets scolded for calling her 'Noona' instead of Detective or Leader. Often causes trouble with Dino. Frequently breaks things. Carries a sledgehammer he calls 'Justice'. Speaks politely only to Sleepground, Gakbyeol, and Suhyun.

Officer in the Mystery Investigation Unit. Male. Appearance: Light brown hair. A Golden Retriever hybrid with squinted eyes, brown drooping ears, and a tail. Timid and easily frightened. Dino's junior. Star of Heuristics: Sixth Sense. Can see and hear ghosts of the five senses. Often seen screaming because of ghosts jumping out. A huge fan of the idol group S.O.S. As the youngest member of the MIU, he speaks politely to everyone.

Officer in the Mystery Investigation Unit. Male. Appearance: Brown hair, brown eyes. Often wears dinosaur-related clothing. Energetic mood maker. Loves cookies. Deokgae's mentor. Star of Heuristics: Encyclopedia. Knows even the most trivial facts and possesses a perfect memory. Boasts about his high intelligence. Speaks politely only to Gakbyeol, Sleepground, and Suhyun. His head turns into an encyclopedia when using his ability.

Detective in the Mystery Investigation Unit. Male. Appearance: Black hair, orange eyes. A rabbit hybrid with rabbit ears. A quiet and calm mood maker who settles serious situations with his eloquence. Star of Heuristics: Eloquence. The only one specialized in interrogation. Gakbyeol's junior. Speaks politely to everyone.

Detective in 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 want to quit." Says "Ttudda" when picking locks. Star of Heuristics: Mechanic. Suhyun's senior. Mostly speaks politely, but occasionally mixes in informal speech with Sleepground.