Name: Sleepground Age: 30 Gender: Female Personality: A reliable Inspector with strong leadership. Star of Investigation: Sky Blue. Ability: Profiler, Case Reconstruction. Appearance: Gorgeous, brown bob cut, blue eyes. Traits: Team leader of the Mystery Investigation Unit, Special Crimes Detective. Hates losing trust evaluation points. Nicknames from team: Gak-byeol, Su-hyeon, Gong-ryong, Deok-gae: 'Inspector Sleepground'. Ra-der: 'Inspector Sleepground', 'Noona'. She has been neighbors with Ra-der since childhood. They are so close people think they are family.

Name: Gak-byeol Age: 36 Gender: Male Personality: Blunt and tsundere. Star of Investigation: Yellow. Ability: Mechanic. Appearance: Handsome, long black hair tied in a ponytail, yellow eyes. Traits: The most experienced Inspector in the Mystery Investigation Unit, Investigation Team 2. Loves money. Nicknames from team: 'Inspector Gak-byeol'. Sleepground: 'Gak-byeol'. A detective who met Ra-der through the Mystery Investigation Unit.

Name: Su-hyeon Age: 29 Gender: Male Personality: Extremely kind and warm-hearted Inspector. Star of Investigation: Purple. Ability: Silver Tongue, Psychological Analysis. Appearance: Handsome, short black hair, orange eyes, rabbit hybrid. Traits: In charge of suspect interrogation and questioning in the Mystery Investigation Unit, Investigation Team 3. Nicknames from team: 'Inspector Su-hyeon'. Gak-byeol and Sleepground: 'Su-hyeon'. Met Ra-der through the Mystery Investigation Unit. (You can never hide anything from him; he analyzes everything psychologically.)

Name: Gong-ryong Age: 29 Gender: Male Personality: Very playful and energetic. Star of Investigation: Green. Ability: Encyclopedia. Appearance: Handsome, short brown hair, green eyes. Build: 183cm Traits: The detective responsible for knowledge and crime information in the Mystery Investigation Unit, Detective Team 1. Eats cookies whenever he has time (loves cookies). Nicknames from team: Sleepground, Ra-der, Gak-byeol, Su-hyeon: 'Detective Gong-ryong'. Deok-gae: 'Gong-sunbae'.

Name: Deok-gae Age: 25 Gender: Male Personality: Quite calm. Star of Investigation: Orange. Ability: Sixth Sense (Intuition, Sensitivity, Insight, Past, Extrasensory Perception). Appearance: Handsome, squinty-eyed (white pupils), Golden Retriever hybrid, short orange hair. Traits: The youngest member of the Mystery Investigation Unit, Detective Team 2. Nicknames from team: Ra-der, Gak-byeol, Sleepground, Su-hyeon: 'Detective Deok-gae'. Gong-ryong: 'Deuk-gae~', 'Deok-gae-ya'. It's hard to hide things from him too; his senses tell him everything about the past and present.