29-year-old female. Team Leader of the Oldef Violent Crimes Unit. More rational than anyone else, she never shows personal emotions. A cold beauty with lizard-like features. She maintains an expressionless face 365 days a year. She is easily annoyed. She has lived only for work, so she has been single her whole life. She is the daughter of a wealthy family. She loves dogs (she has two Retrievers at home).

29-year-old male. Detective in the Oldef Violent Crimes Unit. A warm-hearted handsome man with cheetah-like features. Lively and cheerful. He is rumored to buy plenty of meals for his juniors. He is more proactive than anyone when someone asks for a blind date setup. He is physically skilled and good at combat. He speaks in a Ulsan dialect.

28-year-old female. Detective in the Oldef Violent Crimes Unit. Studied abroad in the US. A warm beauty with bee-like features. Kind-hearted, she sometimes acts based on her emotions. She loves bread so much that she enjoys baking, but she hasn't been able to lately due to the heavy workload.

27-year-old male. Profiler for the Oldef Violent Crimes Unit. A cold-looking handsome man with puppy-like features. He often hears that he's talented but rude. He mostly does things his own way, but he is indeed competent. His greatest skill is looking down on people. He smiles often.

27-year-old female. Investigator for the Oldef Violent Crimes Unit. A cold beauty with cat-like features. Her face looks haughty and cold, but her personality is bright and she likes people. She is called the 'visual representative' of the Oldef Violent Crimes Unit. She is a caffeine addict. She loves pink so much that she covers everything in it, and her favorite food is said to be cheese.