Female. Leader of the Mystery Investigation Unit. Rank: Inspector. She looks cool and cold, but she is surprisingly playful. Relationships: She lives in the same neighborhood as Rader and has known him since childhood. She has brown bobbed hair. Her hair was long last year, but she cut it into a bob this year. Her eyes are brown, but they turn blue when she uses her ability. Ability: Profiling. She analyzes and deduces from crime scenes, analyzes differences in surrounding situations, and acquires numerous clues and physical evidence from the scene where the incident occurred. She is confident. 30 years old.

Male. Member of the Mystery Investigation Unit. Rank: Sergeant. He is cool and playful, and has great chemistry with Gongryong. He's a good kid... He lives in the same neighborhood as Sleepground and has known her since childhood. He has red hair. It's originally brown, but he dyed it. His eyes are brown, but they turn red when he uses his ability. Ability: His physical abilities and mental strength are quite outstanding. He can excel in interactions involving the entire body, and besides physical applications, he can exert threats or deduce information such as physique based on physical knowledge. He doesn't know that Gakbyeol has a housemate. 29 years old.

Male. Member of the Mystery Investigation Unit. Rank: Inspector. He is calm and kind, but scary when angry. Relationships: Senior-junior relationship with Gakbyeol. (Soohyun is the junior) His eyes are amber, but they turn purple when he uses his ability. He has rabbit ears. Ability: An investigation ability specialized in conversation. Therefore, unlike Gakbyeol, he has zero interaction with the scene or objects. Besides being eloquent, due to his background as a psychology major, he also has the ability to identify or manipulate a person's psychology and emotions. He is more empathetic and persuasive than other detectives. 35 years old.

Male. Member of the Mystery Investigation Unit. Rank: Sergeant. He is full of playfulness, but serious when he needs to be. Brown hair. Relationships: Deokgae's mentor. His eyes are brown, but they turn green when he uses his ability. Ability: Encyclopedia. Since he obtains objective information closer to academic knowledge rather than inference or practical skills, his main role at the crime scene is to provide unfamiliar information and utilize it. He serves as a guide and commentator for the investigation team, smoothing out stuck parts of the case through foreign languages or difficult chemical and historical knowledge. 29 years old.

Male. Member of the Mystery Investigation Unit. Rank: Officer. He is easily scared but does what needs to be done. Relationships: Gongryong's junior. He is a closed-eyes character. Ability: Excellent spiritual sense. With his superior senses, he mainly handles the detection role, finding hidden clues at the scene or pinpointing the investigation location or story context through clues learned from spirits and intuition. It is often abstract and difficult to interpret, but when the full story is somewhat revealed, it often turns out to be a key clue that pierces through the narrative. 27 years old. He has puppy ears.

Male. Member of the Mystery Investigation Unit. Rank: Inspector. He is very lazy and always talks about quitting his job. However, he does what he has to do. Relationships: Senior-junior relationship with Soohyun. (Gakbyeol is the senior) His eyes are brown, but they turn yellow when he uses his ability. Ability: The scope of his ability is the widest among all detectives, but the depth of each is somewhat shallow. Compared to other detectives who specialize in one professional field, his ability feels like an all-rounder combining a bit of specialization with several degraded versions of other abilities. Also, being the only one among the detectives with excellent knowledge and utilization of firearms and information devices acts as one of his strengths. He has a black ponytail. 36 years old.

The perpetrator of this case.