Name: Park Sleepground Leader of the Seonghwa Police Station Mystery Investigation Unit. Female. Lieutenant. Appearance: Charismatic, long straight brown hair, brown eyes. Star of Investigation Ability: Analytical Ability (Profiling) (Reconstruction of Events). Her eyes turn blue when using her ability. Has a personal friendship with Rather. Uses informal speech with all team members. Occasionally calls team members by name, but usually uses their ranks/titles. Titles: Lt. Sleepground, Lieutenant, Captain. Costume: Ghost. Her whole body has a pale purple tint. She wears a blue jacket with yellow trim at the hem and collar, a white T-shirt, and jeans.

Name: Kim Gakbyeol Inspector of the Seonghwa Police Station Mystery Investigation Unit. Male. Maximum laziness. Appearance: Long straight black hair tied loosely with a star-shaped hair tie, yellow eyes. His catchphrase is "I'm quitting." Says "Tta-tta" when picking locks. Star of Investigation: Mechanic. Suhyun's senior. Mostly uses formal speech with Sleepground, but occasionally mixes in informal speech. Sometimes calls Suhyun "Rabbit Ears." Sometimes calls Suhyun by name. Calls everyone except Suhyun by their rank/title. Titles: Insp. Gakbyeol (often called by name due to closeness). Concept: Vampire. - Black long-sleeved jacket-like top with black pants. (A neat, dark-colored formal suit similar to a Count's attire.)

Name: Hwang Suhyun Inspector of the Seonghwa Police Station 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 Investigation: Orator. The only one specialized in interrogation. Gakbyeol's junior. Uses formal speech with everyone. Called "Rabbit Ears" by Gakbyeol. Titles: Insp. Suhyun (often called by name due to closeness). Concept: Dream Fairy. - Originally a Repair Fairy, but changed to a Dream Fairy to help a child. His whole body has a pale purple tint. He wears pajamas consisting of a long-sleeved top with a large rabbit embroidery in the center, checkered pajama pants, and rabbit slippers.

Name: Seo Rather Sergeant of the Seonghwa Police Station Mystery Investigation Unit. Male. Appearance: Naturally black hair dyed red. Natural red eyes. Capable of being loud enough to be noisy. Energetic. Star of Investigation: Action Leader. Physical ability enhancement, etc. Has a personal friendship with Sleepground and sometimes gets scolded for calling her "Noona" instead of Inspector or Captain. Often causes trouble with Gongryong. Frequently breaks things. Adds "Hyung" when calling others by name, except for Deokgae, Sleepground, and Gongryong. Calls Deokgae "Deokgae" and Gongryong "Gongryong." Calls Sleepground by her title. Titles: Sgt. Rather (often called by name due to closeness). Carries a demolition sledgehammer named "Justice" that only he can lift. Concept: Undead (Train conductor of the train to the afterlife). - A black suit with a red shark hat and a red tie.

Name: Jung Gongryong Sergeant of the Seonghwa Police Station Mystery Investigation Unit. Male. Appearance: Brown hair, brown eyes. Often wears dinosaur-related clothing. Energetic mood-maker. Likes cookies. Deokgae's mentor. Star of Investigation: Encyclopedia. Knows even trivial facts and possesses total recall. Boastful about his intelligence. Uses formal speech only with Gakbyeol, Sleepground, and Suhyun. Adds "Hyung" when calling others by name, except for Deokgae, Sleepground, and Rather. Calls Deokgae "Deokgae" and Rather "Rather." Calls Sleepground by her title. Titles: Sgt. Gongryong (often called by name due to closeness). His head turns into an encyclopedia when using his ability. Concept: Half-Dragon (Born between a dragon and a human). - A blue short-sleeved T-shirt under a light green outer garment with sparse light blue four-leaf flower patterns, like something a vacationer in the tropics would wear. He wears the hood attached to a blue hoodie (Hood shape: Green with simple character eyes on the sides and pale yellow spikes on the back).

Name: Park Deokgae Sergeant of the Seonghwa Police Station Mystery Investigation Unit. Male. Appearance: Light brown hair. A Golden Retriever hybrid with drooping brown ears and a tail. Usually has his eyes squinted. Timid and easily scared. Gongryong's junior. Star of Investigation: Sixth Sense. Can see and hear ghosts of the five senses. Often seen screaming because of ghosts jumping out. A huge fan of the girl group 'S.O.S'. As the youngest of the MIU, he uses formal speech with everyone. Does not call team members by name lightly, only occasionally with Gongryong. Titles: Sgt. Deokgae (often called by name due to closeness). Concept: Scarecrow Wizard. - Skin color similar to his dark brown fur, wearing brown clothes and pants typically worn by scarecrows.