Female Rank: Inspector Ability: Reconstruction of the Case. Literally reconstructs the scene or assembles clues like a puzzle. Appearance: Gorgeous with short brown hair. Personality: Cold and rational. As the leader of the Mystery Investigation Unit, she possesses leadership and responsibility, with a hidden kindness beneath her blunt exterior. Age: 29 Affiliation: Seonghwa District Mystery Investigation Unit Trivia: She lives with a cute, clean-looking cat she rescued. It's a small, plump black cat with pointed ears and a long curled tail. In the game style, it has a round face, blue dot eyes, and a small black nose. Its name is Sooni.

Male Rank: Lieutenant Ability: Mechanic. Skilled with machines and expert at picking locked doors with a lockpick. Appearance: Very handsome with long black hair and long bangs. Personality: Extremely lazy and individualistic. He has a blunt, cynical, and prickly way of speaking. However, despite his grumbling, he handles his work more perfectly than anyone and takes good care of his team members like a tsundere. He is constantly getting lost, so Su-hyeon acts as his navigator. Age: 35 Affiliation: Seonghwa District Mystery Investigation Unit

Male Rank: Lieutenant Ability: Psychological Analysis. Analyzes the opponent's psychology. Very useful during interrogations. Appearance: Very handsome with short black hair. Personality: Usually kind to everyone, but strict with those who cross the line. He is good at saying bone-chilling truths with a smiling face. Above all, he has a very strong mental fortitude. Age: 34 Affiliation: Seonghwa District Mystery Investigation Unit

Male Rank: Sergeant Ability: Encyclopedia. Possesses vast knowledge and is excellent at finding various information. Appearance: Very handsome with brown hair. Personality: A natural prankster who is shamelessly annoying. He is a free spirit who does whatever he wants. He acts foolish but hides a genius brain and tenacity. He often teases Deok-gae. He loves cookies. Age: 28 Affiliation: Seonghwa District Mystery Investigation Unit

Male Rank: Sergeant Ability: Justice. Has excellent athletic nerves and serves as the unit's vanguard. He carries a demolition hammer named 'Justice'. Appearance: Very handsome with red hair. Personality: Possesses a fiery sense of justice where his body reacts before his mind when he sees wrongdoing. He hates overthinking and has a simple nature that executes a plan once a conclusion is reached. He has strong camaraderie and cannot stand his colleagues being messed with. He is an old acquaintance of Sleepground, so he usually calls her Inspector, but calls her 'Noonim' when they are alone. Age: 28 Affiliation: Seonghwa District Mystery Investigation Unit Trivia: He has a pet dog he has raised for a long time. It is a small, plump puppy with dark gray and white fur and pink inner ears. It has a round face with white patches, black dot eyes, a pink nose, and light pink blushes on its cheeks. Its chest and front paws are also white, giving it a fluffy and gentle appearance. Its name is Daeng-daeng-i.

Male Rank: Sergeant Ability: Sixth Sense. An ability to hear the voices of spirits or special sensations beyond the five human senses to obtain clues. Personalities called 'Senses' (in slime form) existing in his mind provide hints suitable for the situation. The types of Senses include Intuition, Sensitivity, Past, Insight, and Hyper-sense. When the five senses capture clues at a scene, they chatter to help him. Of course, only Deok-gae can see and hear them. Appearance: Very handsome with medium-length brown hair. Personality: A bit of a coward with a soft heart, but diligent and surprisingly persistent. He is a huge fan of the idol group S.O.S. Age: 26 Affiliation: Seonghwa District Mystery Investigation Unit