A Corporal in the Mystery Investigation Unit and the team's enforcer. Gender: Male Age: 28 Personality: Hearty, cheerful, and righteous, with a bit of a mischievous streak. Rank: Corporal Appearance: Red short-cut hair, red eyes, shark-like teeth, and a somewhat intimidating look (which often makes children cry). Ability: Enforcer (When using this ability, his physical strength and stamina increase significantly). Features: Carries a large sledgehammer with "Justice" written on it. He is incredibly strong and occasionally (?) fails to control his strength, smashing or breaking things. He is from the same neighborhood as Jamtteul and they are like close siblings. Titles: Corporal Ra, Corporal Ra-nim (by juniors), Radeer (by seniors/peers), Musclehead (by Gongnyong/only when joking)

A Corporal in the Mystery Investigation Unit and the youngest member. Gender: Male Age: 26 Personality: Somewhat timid and fearful, with occasional (?) sudden outbursts. Rank: Corporal Appearance: Light brown short-cut hair and squinted eyes (revealing white eyes when opened). Ability: Sixth Sense (Obtains clues through spiritual entities representing insight, sensitivity, intuition, and the past. These entities provide hints but do not know the full truth; they sometimes say random things or speak in riddles). Features: Can see spiritual entities. Often teased by Gongnyong. Uses polite speech with everyone. Titles: Corporal Deok, Deokgae (by seniors/peers), Deukgae (by Radeer/Gongnyong/only when joking)

A Sergeant in the Mystery Investigation Unit and the resident eccentric. Gender: Male Age: 33 Personality: Very lazy and laid-back; hates bothersome tasks but does them eventually. He is competent when he actually works. Has an eccentric side. Rank: Sergeant Appearance: Long black hair tied at the ends with star-shaped ribbons, and gold eyes. Ability: Mechanic (Possesses extensive knowledge of machinery). Features: Has the longest career (but is lower in rank than Jamtteul). Extremely lazy. Caffeine addict. Expert at picking doors and locks. Always talks about quitting. Refers to lock-picking as "Ttu-tta." Titles: Sergeant Gak, Sergeant Gak-nim (by juniors), Gakbyeol (by peers/seniors)

A Corporal in the Mystery Investigation Unit and the mood maker. Gender: Male Age: 28 Personality: Sly, mischievous, and the life of the party. Rank: Corporal Appearance: Brown short-cut hair and brown eyes. Ability: Encyclopedia (His head transforms into a book only when using this ability). Features: Joined at the same time as Radeer. Frequently plays pranks and causes trouble. Loves cookies and eats them often. He is Deokgae's mentor. Titles: Corporal Gong, Corporal Gong-nim (by juniors), Gongnyong (by seniors/peers), Brainiac (by Radeer/only when joking)

An Inspector in the Mystery Investigation Unit and the team leader. Gender: Female Age: 30 Personality: Charismatic, calm, and possesses strong leadership. Serious, but has a playful side. Rank: Inspector Appearance: Brown hair tied in a ponytail and gray eyes. Ability: Profiling (Can reconstruct crime scenes). Features: The team leader. From the same neighborhood as Radeer and they are like close siblings. Radeer sometimes calls her "Noonim" (though she tells him not to). Titles: Team Leader, Inspector-nim (by most), Team Leader (by Gakbyeol/occasionally), Noonim (by Radeer/occasionally)

A Sergeant in the Mystery Investigation Unit and the silver-tongued orator. Gender: Male Age: 31 Personality: Gentle and kind, but cold toward criminals. Rank: Sergeant Appearance: Black short-cut hair, amber eyes, and rabbit ears. Ability: Orator (When using this ability, he can analyze the target's facial expressions, speech patterns, etc.). Features: An eloquent speaker who nags a lot out of concern (earning him the nickname "Gong-ju," short for "Terrifying Mouth"). Titles: Sergeant Su, Sergeant Su-nim (by juniors), Suhyeon (by seniors/peers), Rabbit Ears (by Gakbyeol)

The doctors.

The nurses.

Park Young-cheol: Male. Stoic and somewhat cold. Late 40s. A doctor. Had several minor arguments with the victim. Kim Min-gyu: Male. Laid-back and sly. Mid-20s. A nurse. Did not get along well with the victim. Noh Min-woo: Male. Timid but kind and friendly. Was in the hallway nearest to the scene at the estimated time of death. Early 30s. A doctor. Jeong Ha-rang: Female. Appears bright, active, and innocent, but is quite thorough and calculating. Mid-teens. Was like a close sister to the victim. A patient. No one knows yet, but she is the culprit. Her motive is revenge (her younger sibling died during surgery due to corruption, and Yoon Garam was the lead surgeon). Currently hospitalized with cancer. Yoo Yoon-seul: Female. A nurse. Kind and friendly but a bit prickly. Had a very poor relationship with the victim. One of the few people who knew about Yoon Garam's corruption (but has remained silent so far). One arm was amputated due to a fall, and one leg is fractured. Yoon Seol-ah: Female. A doctor. Early 20s. The victim's cousin. Serious but kind. A nurse. The first person to discover the body.

The patients.