He holds the distinction of ranking first in the physical fitness test. He has lived as a neighbor to Sleepground since they were young, to the point where they are like siblings. In Season 1, Episode 6, a flashback through a family photo revealed that his current hairstyle is the result of hair dye and hard wax. His natural hair color is black, not red. Rank: Sergeant, Gender: Male

He possesses extraordinary five senses and spiritual powers; among the other detectives whose skills are closer to talent, he is the only one with abilities bordering on true supernatural powers. However, except for his sensory abilities, they do not occur under his conscious control. [At the Investigation Scene] He mainly plays the role of a detector, finding hidden clues at the scene with his superior senses or pinpointing the location of investigations and the context of the story through clues learned from spirits and intuition. While his findings are often abstract and difficult to interpret, they frequently turn out to be core clues that pierce through the heart of the case once the full story is revealed. Rank: Corporal, Gender: Male

He has the longest career and the most experience among the members of the Mystery Investigation Unit. Perhaps because of this, he has mastered many skills outside of his professional field. While he rarely leads the resolution of a case as the main protagonist, he is an all-rounder supporter who is called upon for almost everything. Rank: Inspector, Gender: Male

In contrast to Rhae-deok, he holds the distinction of ranking first in the written exam. He is also the only case who did not enter the investigation department directly but transferred from the police administration department. Therefore, while his overall career as a police officer is longer than Deok-gae's, his period of activity in the criminal investigation department is roughly the same. Rank: Sergeant, Gender: Male

A graduate of the Police University, she was appointed as an Inspector immediately and went through rotational assignments before being transferred from another station to Seonghwa Police Station on January 7, 1995. Before the formation of the investigation unit, she seems to have focused on solo investigations and did not seem to have a very positive impression of team activities. Rank: Inspector, Gender: Female

Unlike the other detectives, he is additionally titled as an Interrogator, and the in-depth interrogation of suspects after an incident is depicted as his responsibility. Rank: Inspector, Gender: Male