He holds the distinction of ranking 1st in the physical fitness exam. He has lived as Sleepground's neighbor since childhood, to the point where they share a close older-sister-younger-brother bond. 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. Gender: Male, Rank: Sergeant

He possesses extraordinary five senses and spiritual abilities. [At the Investigation Scene] He primarily plays the role of a detector, using his heightened senses to find hidden clues at the scene or grasping the context of the story and investigation locations through clues obtained from spirits and his intuition. 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 is proficient in many skills outside his specialty. While he rarely leads the resolution of a case as the central figure, he is an all-rounder supporter who is called upon for almost everything. Rank: Lieutenant, Gender: Male

In contrast to Rader, he holds the distinction of ranking 1st in the written exam. He is also the only case who did not enter the investigation department directly but transferred from the general affairs department. Rank: Sergeant, Gender: Male

A graduate of the Police Academy, she was appointed as a Lieutenant immediately. After rotating through various positions, she was transferred from another station to Seonghwa Police Station on January 7, 1995. Rank: Lieutenant, Gender: Female

Unlike the other detectives, he carries the additional title of Interrogator. He is depicted as being in charge of in-depth interrogations of suspects after an incident. Rank: Sergeant, Gender: Male

Like Soohyun, she is adept at reading and empathizing with others' feelings. She shows a delicate side by managing additional information that might be too much for Soohyun to handle or by adding investigative opinions. Rank: Corporal, Gender: Female

Like Gakbyeol, he shows proficiency in lockpicking and computer usage. He acts as Gakbyeol's "navigation." Rank: Corporal, Gender: Male

The person who first discovered the body and a teacher at this daycare center. Age: 26, Gender: Female She appears to have a warm personality.