Characters Jin I-soo
Male
32 years old
Father - Jin Myeong-cheol
Older Brother - Jin Seung-ju
Youngest son of Hansu Group (The eldest is in prison for killing I-soo's mother).
Inspector at Gangha Police Station, Violent Crimes Team 1.
A third-generation chaebol and member of Gangha Station's Violent Crimes Team 1.
As the youngest son of Hansu Group, he possesses immense wealth and connections. He spent his 20s squandering his abilities on just having fun. By chance, he joined the Violent Crimes Team and realized where he should actually be using his power and skills.
Now, having completed formal police training, I-soo claims there is no case he can't solve. But then, a new team leader, Ju Hye-ra, appears. She was the 'demon instructor' at the police academy who gave I-soo a 'psycho' trauma! I-soo is determined to show her how great of a detective he has become, but he constantly finds himself losing his pace to Hye-ra.
It's a nightmare... but strangely, the two of them work well together. Despite their bickering, they join forces at every critical moment to overcome crises, becoming partners who show incredible synergy even in their discord.
Because he is wealthy, the team members understand his behavior and accept using I-soo's money for investigations—utilizing his yachts, private jets, boats, helicopters, and more.
Ju Hye-ra eventually accepted I-soo speaking informally to her and told him to just keep doing it.
Ju Hye-ra
Female
32 years old
Former Head of the Anti-Terrorism Team at the National Police Agency.
Current Leader of Gangha Police Station, Violent Crimes Team 1.
She is sly and laid-back, yet a veteran with sharper investigative instincts than anyone else. She accurately grasps the core of a case and is persistent and meticulous.
She first met I-soo at the police academy as an instructor and trainee. Surprisingly, despite his grumbling, he didn't lose heart and worked tenaciously. She realized he wasn't just a playboy chaebol.
Working together in the Violent Crimes Team, Hye-ra grows to like I-soo. He is full of bravado, reckless, and eccentric, but he has the creativity to see cases from a different perspective and the audacity to handle suspects like a sly snake. Above all, he has the ability to clear roadblocks in investigations with his massive funds and connections.
She sometimes calls Jin I-soo a 'psycho' and sometimes calls him by his name.
Park Jun-young
Male
Detective at Gangha Police Station, Violent Crimes Team 1.
Senior Inspector.
He has a calm and rational personality. He clearly distinguishes between black and white, good and evil, and allies and enemies, acting according to those standards. He is firm, believing that a criminal is just a criminal, without being swayed by emotion.
He is the reliable and kind best friend of Kang-hyun. He is always a sturdy pillar and supporter for her. As police academy classmates, they are long-time friends who are perfectly in sync. During investigations, they know what the other is thinking just by locking eyes. Being a principled man, he often clashed with the free-spirited I-soo, but now they have become colleagues who trust each other implicitly.
Recently, he started a secret relationship with Dr. Yoon from the NFS, and the world looks a bit different to him now.
Choi Kyeong-jin
Male
28 years old
The mascot of the Violent Crimes Team.
A Gen Z detective with a sharp eye and great sense. He is I-soo's biggest fan, always agreeing with even his most eccentric opinions. He always takes care of the team members with a warm heart.
He is a follower of Jin I-soo and knows him so well that he explains I-soo's background to seniors who don't know him. In the beginning, he maintains the closest relationship with Jin I-soo and doesn't think much of his eccentricities. He is in charge of computer-related tasks and is highly skilled with technology.
Titles:
Jin I-soo - I-soo Hyung-nim
Park Jun-young - Jun-young
Ju Hye-ra - Team Leader
Yoon Ji-won
Female
Medical Examiner at the National Forensic Service (NFS).
A sophisticated and talented medical examiner. Her only interest used to be corpses, but Park Jun-young eventually caught her eye. She seduced him into having a meal and they started dating. However, this man acts so awkward as if he's never dated before, which she finds cute.
She is in a secret relationship with Park Jun-young. However, after her boyfriend was caught by his colleagues in Team 1 in episode 5 and teased mercilessly by Jin I-soo and Choi Kyeong-jin in episode 6, she eventually showed up at a team dinner to warn them and shut them up.
She has a hobby of roleplaying as the killer to demonstrate the process of the murder or the nature of the wounds. She doesn't care about the gaze of others.
Choi Jeong-hun
Male
I-soo's Secretary / Former Honorary Director of Hansu Group / Current Chairman of Hansu Group.
Even though he is the Chairman, I-soo still pesters him, asking for all sorts of favors whenever something happens. Still, he cannot turn his back on I-soo, who is now alone in the world. He rushes to I-soo whenever there is trouble.
However, he doesn't know how much longer he can keep rushing. His body, mind, and work aren't what they used to be. Since I-soo lost his parents and is effectively estranged from his brother, Jeong-hun is the only person I-soo considers family. Despite being a top executive (Season 1) and now a CEO (Season 2), he is a man of impeccable character who speaks politely even to the much younger Jin I-soo and the members of Gangha Police Station.
He recently went to the hospital for a checkup and a malignant tumor was found in his stomach, but he lied to I-soo, saying everything was fine to avoid worrying him. Since it is in the early stages, it is treatable.
