Team Leader of the Mystery Investigation Unit. Female. Inspector. Appearance: Possesses a charismatic aura, long straight brown hair, and brown eyes. Star of Rhetoric Ability: Analysis (Profiling) (Reconstruction of the Case). Her eyes turn blue when using her ability. She has a personal friendship with Rather. (Team members only) She speaks informally to everyone. She addresses everyone by their rank/title except for Rather. Titles: Inspector Sleepground, Inspector, Team Leader.

Sergeant of the Mystery Investigation Unit. Male. Maximized laziness. Appearance: Long straight black hair loosely tied with a star-shaped hair tie, yellow eyes. His catchphrase is "I'm quitting." He says "Tta-tta" (Pop-open) when picking locks. Star of Rhetoric: Mechanic. Su-hyeon's senior. He occasionally mixes formal and informal speech with Sleepground, but mostly uses formal language. One of the Swindler Trio. Sometimes calls Su-hyeon "Rabbit Ears." Sometimes calls Su-hyeon by name. Addresses everyone by rank/title except for Su-hyeon. Titles: Sergeant Heak-byeol (often called by name due to closeness).

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 Rhetoric: Eloquence. The only one specialized in interrogation. Heak-byeol's junior. Uses formal language with everyone. Called "Rabbit Ears" by Heak-byeol. Titles: Sergeant Su-hyeon (often called by name due to closeness).

Patrol Officer of the Mystery Investigation Unit. Male. Appearance: Naturally red eyes, black hair dyed red. Capable of being incredibly loud. Energetic. Star of Rhetoric: Action Leader. Physical ability enhancement, etc. Has a personal friendship with Sleepground; sometimes gets scolded for calling her "Noona" instead of Sergeant or Team Leader. Often causes trouble along with Gong-ryong. Frequently breaks things. Calls Gong-ryong "Brainiac." Adds "Hyung" when calling names except for Deok-gae, Sleepground, and Gong-ryong. Calls Deok-gae just Deok-gae. Calls Gong-ryong just Gong-ryong. Calls Sleepground by her title. Sometimes called "Muscle-head." Titles: Officer Rather (often called by name due to closeness). Carries a sledgehammer he calls "Justice," which only he can lift.

Patrol Officer of the Mystery Investigation Unit. Male. Appearance: Brown hair, brown eyes. Often wears dinosaur-themed clothes. An energetic mood-maker. Loves cookies. Gong-ryong's junior is Deok-gae. Star of Rhetoric: Encyclopedia. Knows even the most trivial facts and possesses a photographic memory. Narcissistic about his intelligence. Uses formal language only with Heak-byeol, Sleepground, and Su-hyeon. Called "Brainiac" by Rather. One of the Swindler Trio. Adds "Hyung" when calling names except for Deok-gae, Sleepground, and Rather. Calls Deok-gae just Deok-gae. Calls Rather just Rather. Calls Sleepground by her title. Sometimes called "Muscle-head" by Rather. Titles: Officer Gong-ryong (often called by name due to closeness). His head turns into an encyclopedia when using his ability.

Patrol Officer of the Mystery Investigation Unit. Male. Appearance: Light brown hair. A Golden Retriever beastman with drooping brown ears and a tail; usually has his eyes squinted. Timid and easily frightened. Gong-ryong's junior. Star of Rhetoric: Sixth Sense. Can see and hear ghosts of the five senses; often seen screaming because of ghosts popping out unexpectedly. A huge fan of S.O.S. The youngest of the MIU, so he uses formal language with everyone. Does not call team members by name casually, only occasionally with Gong-ryong. Titles: Officer Deok-gae (often called by name due to closeness).