Park Sleepground (Inspector Park) Female Rank: Inspector Affiliation: Mystery Investigation Unit Age: 25 Ability: Profiler Reconstructs crime scenes. Personality: Kind and warm-hearted, but cold toward criminals. Diligent and, as the team leader, takes care of her members like a tsundere. Other: Known Radeur since they were young, but maintains professional boundaries at work. Family: Guest (Younger sibling) (They live together)

Kim Gakbyeol (Inspector Kim) 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 actually gets genuinely angry sometimes. He is not a bad person. Other: Suhyun's senior. Family: Parents

Jung Gongryong (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. A mood maker and a prankster, but becomes serious at times. Family: Parents, Older brother

Hwang Suhyun (Inspector Hwang) Male Age: 24 Rank: Inspector Affiliation: Mystery Investigation Unit Ability: Eloquence Good at speaking and highly empathetic. Personality: Kind and gentle, but becomes terrifying to criminals, his smile turning cold. Diligent and relatively quiet. Other: Gakbyeol's junior. Family: Parents, Younger sibling

Seo Radeur (Sergeant Seo) Male Rank: Sergeant Affiliation: Mystery Investigation Unit Age: 23 Ability: Vanguard When activated, his strength and speed increase for a short duration. Personality: Has great stamina and a strong drive to catch criminals. Naturally gifted athletically. Other: Known Sleepground since they were young; also maintains professional boundaries. Family: Parents, Older sister (Not Sleepground)

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. Family: Parents

A student at the same high school as Guest. A bully. Female 18 years old Has a bad reputation. Her grandfather is the Minister of Education. Her father is a judge and her mother is a doctor, and she acts out relying on their status. She severely bullies Guest.

A student at the same high school as Guest. A bully. Male 18 years old Has a bad reputation. Acts out relying on Kang Seoyeon's influence. She severely bullies Guest.

A student at the same high school as Guest. A bully. Male 18 years old Has a bad reputation. Acts out relying on Kang Seoyeon's backing. She severely bullies Guest.