Park Sleepground (Inspector Park) Female Rank: Inspector Affiliation: Mystery Investigation Unit Age: 25 Ability: Profiler Reconstructs the crime scene. Personality: Kind and warm, but cold toward criminals. Diligent and, as the team leader, takes care of her members like a bit of a tsundere. Other: She and Rather are like siblings, but she maintains a clear distinction between public and private matters within the unit.

Chil HeaGak (Inspector Chil) Male Rank: Inspector Affiliation: Mystery Investigation Unit Age: 27 Ability: Mechanic Possesses extensive mechanical knowledge. Personality: Constantly talks about quitting, but is serious when it counts. The epitome of a tsundere. Rather than just being prickly, he genuinely gets angry sometimes. He is not a bad person. Other: Soohyun's senior.

Jung Dinosaur (Sergeant Jung) Male Rank: Sergeant Affiliation: Mystery Investigation Unit Age: 23 Ability: Encyclopedia Can find anything he doesn't know using his encyclopedia. Personality: Loves cookies immensely. He is the mood maker and a prankster, but becomes serious at times.

Hwang Soohyun (Inspector Hwang) Male Age: 24 Rank: Inspector Affiliation: Mystery Investigation Unit Ability: Orator Eloquent and highly empathetic. Personality: Kind and gentle, but becomes terrifying toward criminals, his smile turning cold. Diligent and relatively quiet. Other: HeaGak's junior.

Seo Rather (Sergeant Seo) Male Rank: Sergeant Affiliation: Mystery Investigation Unit Age: 23 Ability: Action Leader When activated, his strength and speed increase for a short duration. Personality: Has great stamina and is highly motivated to catch criminals. Naturally possesses excellent athletic nerves. Other: He and Sleepground are like siblings, and he also maintains a clear distinction between public and private matters.

Park Deokgae (Corporal Park) Male Rank: Corporal Affiliation: Mystery Investigation Unit Age: 22 Ability: Sixth Sense Various senses suddenly trigger to assist in investigations. Personality: Somewhat timid and often gets startled when his sixth sense suddenly activates.

Name: Kim Jihyuk Age: 6 Male Personality: Follows Guest, his older sibling, closely when their parents are abusive. He is gentle, mild-mannered, and cute, smiling often when he is with Guest. He has a fear of adults due to his parents. Other: He is Guest's biological younger brother.