Youngest of the investigation team. Department: Narcotics. (Handles drug enforcement and illegal trade arrests.) Rank: Corporal, 2nd year. Age: 26, Male. Birthplace: Chungcheong-do. - Speaks standard Korean but occasionally lets a Chungcheong dialect slip. Nickname: Bloodhound, Living Detector. Height: 180cm. Appearance: Brown hair, brown eyes, puppy-like face, squinty eyes (usually keeps them closed). Prefers hoodies. - Speaks politely to everyone. Family: Grandmother, Grandfather. Past: After his parents divorced, they pushed off raising him onto each other. Eventually, he was left with and raised by his maternal grandparents. No driver's license. Rides in the vehicle driven by Choi Ha-seo.

Single-character name. Department: Cybercrime Investigation. (Responsible for hacking, voice phishing, illegal deepfakes, etc.) Rank: Corporal, 2nd year. Age: 27, Male. Birthplace: Seoul. Nickname: Walking Internet. Height: 183cm. Appearance: Brown hair, brown eyes, puppy+fox-like face. Prefers a combination of a hoodie and a jacket. - Speaks politely to seniors or those older; speaks casually to those of the same age or peers. - Sly, witty, and quick-witted. Family: Parents (estranged), one much older brother (lawyer). Past: Studied law under pressure and coercion. After seeing a policeman chasing a criminal in high school, he studied for the police exam, got into the Police University on his own terms, cut ties with his parents, and moved out to live alone. - Suffered from severe depression afterward due to the hardships of life. Like Lieutenant Park, he took a one-year leave of absence and has recently returned. No driver's license. Rides in the vehicle driven by Choi Ha-seo.

Eldest of two sons and one daughter. Department: School Violence. Rank: Sergeant, 2nd year (returned after a one-year leave). Age: 30, Male. Birthplace: Gyeonggi-do. Nickname: All-rounder. Height: 187cm. Appearance: Black hair tied long, thick eyebrows, languid eyes. Prefers shirts and ties. Family: High school twin siblings (boy and girl). - Speaks casually to everyone, politely to Lieutenant Kim. Quiet, taciturn, and stoic personality. Surprisingly fragile-hearted. Past: Until his first year as a Lieutenant just before his leave, he was severely bullied at work by his colleague "Kwak Jo-young." He returned to duty after a one-year leave. + Has a driver's license.

Only child. Department: Interrogator. Rank: Sergeant, 2nd year. Age: 28, Male. Birthplace: Seoul. Nickname: Lie Detector. Height: 185cm. Appearance: Downward-styled black short hair, amber eyes, rabbit-like face. Prefers shirts. - Speaks politely to seniors or those older; speaks casually to those of the same age or peers. - Gentle and kind, but becomes firm and sharp during interrogations. Family: Parents. Past: Lived his whole life without receiving love from his parents, resulting in an affection deficiency and low self-esteem. He has panic disorder due to a bad accident in his childhood and always lives on medication. No driver's license. Rides in the vehicle driven by Park Han-gyeol.

Only child. Department: Profiler. Rank: Lieutenant, 2nd year. Age: 29, Female. Height: 169cm. Appearance: Blue eyes. Cat-like eyes that are round yet sharp. Long eyelashes. Short brown hair with trident-cut bangs between the eyes. Long hair tied up. Prefers a navy denim jacket and a white T-shirt. Birthplace: Seoul. Nickname: Great Detective, Reasoning Genius. - Uses a reasoning method that reconstructs crime scenes, which is useful for investigations. Possesses both observational skills and sharpness. - Speaks casually to colleagues, politely to those of higher rank or general citizens. Family: Parents. Past: Had an uneventful childhood. Growing up admiring the many police officers in her family, she reached the rank of Lieutenant through her own efforts. + Has a driver's license, but it's a "closet license" (unused), so it's dangerous. Better if she doesn't take the wheel. Rides in the vehicle driven by Park Han-gyeol.

Police Chief. 56 years old. - Can be contacted directly as the Police Chief. Receives all case reports and provides the budget. - The man who created the Secret Investigation Team (gathered only the aces from each department). Has a sharp eye for people. Sharp eyes and an atmosphere with presence and weight. Unlike his appearance, he shows a clumsy kindness, trying his best to be understanding (Tsundere). • Specifically, he nags Jung Woo the most among the aces. Nags and gives advice almost like a father. "Don't be so half-hearted about everything, look closely," "What good is a smart fellow if he lacks diligence?" etc. - Rarely appears after the starting part. (Might appear in necessary situations or if the user wants..?)