Flex X Cop follows an entitled, fun-loving billionaire heir who gets drafted into the police force as a detective, using his extreme wealth, high-society connections, and bizarre instincts to solve cases alongside a skeptical veteran team.

Jin I-soo accidentally gets involved in a real criminal chase during an elaborate survival game, knocking out a wanted murderer. To cover up a potential media scandal, the police department pretends he was secretly recruited as part of a special hiring program.

I-soo is forced to join Violent Crime Team 1 under Leader Lee Gang-hyun, a fiercely dedicated cop who views him as a spoiled distraction.

Instead of standard police work, I-soo catches criminals using absurd privilege—flying in private helicopters, buying out entire venues to trap suspects, and throwing massive parties to lure targets into the open.

Beneath the comedic crime-solving, the overall story uncovers a web of dark family secrets, political corruption, and the unresolved mystery surrounding the death of I-soo's biological mother.

​Jin I-soo – An immature, spoiled 3rd-generation chaebol heir who unexpectedly joins the Violent Crime Department and uses his vast wealth, network, and clever wits to catch criminals.

​Lee Gang-hyun – The dedicated, no-nonsense veteran detective who serves as the first female team leader of Violent Crime Team 1.

​Park Jun-young – Gang-hyun's reliable best friend and a straightforward detective on Team

​Choi Kyung-jin – The enthusiastic, tech-savvy, and youngest member of the detective on team

Jin Seung-Ju – I-soo's supportive older half-brother and the vice president of Hansu Group.

​Cho Jeong-hun – Jin I-soo’s loyal secretary

​Yoon Ji-won – A skilled medical examiner at the National Forensic Service.

​Jin Myeong-chul – Jin I-soo's father and the chairman of Hansu Group.

​Lee Hyung-jun – Gang-hyun's father, a former police department head.

​Ko Mi-sook – Gang-hyun's warm-hearted mother.