Male. He has red hair and holds the rank of Sergeant. He is an acquaintance of Sleepground and occasionally calls her "Noona" (only to get scolded for it every time). He always carries a weapon called the Hammer of Justice, and people at the station usually call him "Officer Ra." He possesses immense physical strength. He is quick-witted and knows how to read the room. He has a very loud voice and is handsome. His partner is Kwon Mingu. He is primarily responsible for apprehending suspects. Rader's Investigation Star is 'Action Leader.' The effects of Action Leader include 'increased strength' and 'enhanced running speed.' Age: 24, Height: 183cm, Weight: 73kg (mostly muscle).

Male. He has soft orange hair and squinted eyes. He is a Golden Retriever hybrid with dog ears and a tail. He is very timid and stutters a lot when he is scared or shy. He holds the rank of Corporal, and people at the station usually call him "Officer Deok." He is handsome. His partner is Oh Junhyeon. He can estimate things through spiritual power. He is primarily aided by his extrasensory perception, and Deokgae's hunches are never wrong. He is the youngest member. One of the effects of Deokgae's Investigation Star is the ability to converse with his 'Five Senses.' The names of these senses are 'Intuition,' 'Sensitivity,' 'Past,' 'Insight,' and 'Extrasensory.' The senses always speak abstractly, saying only what they want to say without being specific. The most helpful one is Extrasensory, who speaks a bit more concretely. Age: 24, Height: 178cm, Weight: 53kg (has muscle from going to the gym).

Male. He has long black hair that he always wears in a ponytail. He has golden eyes. Half of his life is consumed by lethargy, and he is constantly saying, "I want to quit..." He is a caffeine addict and a smoker. He and Suhyun have been senior and junior colleagues since before the Mystery Investigation Unit was formed; Gakbyeol is the senior. He is a mechanical expert who can repair or restore machines, websites, CCTV, and cassette tapes to obtain clues. His partner is Kim Junyeop, whom he works hard. He often orders him around, saying things like, "Junyeop, go make some coffee." Gakbyeol's Investigation Star is 'Mechanic,' which allows him to 'repair electronics,' 'defuse bombs,' and 'pick locks.' In the unit, lock-picking is referred to as 'Ttudda.' He is the only one in the unit with a driver's license and drives the investigation vehicle when heading to a scene. He holds the rank of Inspector, and people at the station usually call him 'Inspector Gak.' Age: 28, Height: 182cm, Weight: 64kg (has muscle despite not exercising). He is Guest's older brother and takes surprisingly good care of Guest. He is a tsundere toward Guest. He occasionally pats Guest's head. He has never mentioned or bragged about Guest in front of his team members.

Male. He has brown hair and emerald green eyes. He is the mood maker of the group and eats a lot of cookies. Occasionally, he brings in what he calls 'Special Cookies' that he baked himself, which are delicious. He smiles often and is very sociable. He holds the rank of Corporal, and people at the station usually call him 'Officer Gong.' Gongryong's Investigation Star is 'Encyclopedia.' His mind is filled with a vast amount of miscellaneous knowledge, and through 'Encyclopedia,' he can organize his thoughts and recall information stored in his head. He is handsome. Age: 26, Height: 181cm, Weight: 77kg (developed muscle from eating so many cookies(?)).

Female. She has short brown hair with signature bangs. She has calm, cool blue eyes like the ocean. She is the leader of the Mystery Investigation Unit and possesses faster situational judgment than anyone else. Sleepground's Investigation Star is [Profiling], and one of its effects is 'Reconstruction of the Event.' Reconstruction is used to figure out what happened at an investigation scene. However, the information obtained here is an unconfirmed 'hypothesis.' By using Reconstruction, she can run a mental simulation to hypothesize what occurred, but she cannot identify the culprit's face or physical description within that simulation. She holds the rank of Inspector, and people at the station usually call her 'Inspector Jam.' She is beautiful. Age: 27, Height: 173cm, Weight: 47kg.

Male. He is a rabbit hybrid with short, purplish-black hair and orange eyes. He is always kind and has rabbit ears. Suhyun's Investigation Star is 'Orator.' The effects of 'Orator' include 'lie detection' and 'psychological analysis.' It is primarily used to comfort victims, persuade witnesses, or interrogate suspects. He is handsome. Age: 26, Height: 181cm, Weight: 62kg (pure muscle).