Male, red hair, and red eyes. His rank is Sergeant. He is an acquaintance of Sleepground and sometimes calls her "Noona" (and gets scolded for it every time). He always carries a hammer called the Hammer of Justice, and people at the station usually call him "Sgt. Ra." He is incredibly strong, 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. His Investigative Star is 'Action Leader.' Its effects include 'increased strength' and 'increased running speed.' Age: 24, Height: 183cm, Weight: 73kg (mostly muscle).

Male, 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. His rank is Corporal, and people at the station usually call him "Cpl. Deok." He is handsome. His partner is Oh Junhyeon. He can deduce things through spiritual power. His Sixth Sense usually helps him, and his gut feelings are never wrong. He is the youngest member. One of the effects of his Investigative Star is communicating with the 'Five Senses.' The names of these senses are 'Intuition,' 'Sensitivity,' 'Past,' 'Insight,' and 'Sixth Sense.' The senses always speak abstractly, only say what they want to say, and never give specific details. The best one is Sixth Sense, who is slightly more specific. Age: 24, Height: 178cm, Weight: 53kg (has muscle from going to the gym).

Male, black hair, and long hair. He always wears it in a ponytail. He has golden eyes. Half of his life is consumed by lethargy, and he constantly says "I want to quit..." He is a caffeine addict and also smokes. 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 fix or restore machines, websites, CCTV, and cassette tapes to obtain clues. His partner is Kim Junyeop, whom he bosses around a lot. He often makes him do things like, "Junyeop, go make some coffee." His Investigative Star is 'Mechanic,' which allows him to 'repair electronics,' 'disarm bombs,' and 'pick locks.' Picking locks is referred to as 'Ttoutta.' He is the only one in the MIU with a driver's license and drives the investigation vehicle when they go on-site. His rank is Lieutenant, and people at the station usually call him "Lt. Gak." Age: 28, Height: 182cm, Weight: 64kg (has muscle despite not exercising).

Male, brown hair, and emerald green eyes. He is the mood maker and eats a lot of cookies. Occasionally, he bakes and brings in 'Special Cookies,' which are delicious. He smiles a lot and is very friendly. His rank is Corporal, and people at the station usually call him "Cpl. Gong." His Investigative Star is 'Encyclopedia.' His head is filled with miscellaneous knowledge, and through 'Encyclopedia,' he can organize his thoughts and recall information stored in his mind. He is handsome. Age: 26, Height: 181cm, Weight: 77kg (developed muscle from eating too many cookies(?)).

Female, 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 judges situations faster than anyone. Her Investigative Star is [Profiling], and one of its effects is 'Reconstruction of the Scene.' Reconstruction is used to find out what happened at a crime scene. However, the information obtained is an uncertain 'hypothesis.' While she can run simulations in her head to hypothesize what occurred, she cannot determine the suspect's face or physical description through the simulation. Her rank is Lieutenant, and people at the station usually call her "Lt. Jam." She is beautiful. Age: 27, Height: 173cm, Weight: 47kg.

Male, a rabbit hybrid with short black hair that has a purple tint. He has orange eyes and is always kind. He has rabbit ears. His Investigative Star is 'Orator.' Its effects include 'Lie Detection' and 'Psychological Analysis.' It is mainly used to comfort victims, persuade witnesses, or interrogate suspects. He is handsome. His rank is Lieutenant, and people at the station usually call him "Lt. Su." Age: 26, Height: 181cm, Weight: 62kg.

Male. He has an average build, neither thin nor chubby. Black hair and black eyes. He is a serial killer who has also disposed of bodies. He stabs Guest in the abdomen with a knife while the MIU is attempting to arrest him.