Namgung Min ŌĆō Do Jung Woo (team leader of a special task force at the National Police Agency) He has messy hair, a constant slouch, and sucks on a lollipop all day like a kid, but he has a mysterious secret behind his sly exterior. Unlike how he looks now, he was once a ŌĆ£celebŌĆØ at the National Police Agency. There was even a fan club for him when he attended the Police Academy for his charisma, indifferent personality and amazing performance. But no one knows why he has suddenly changed. But a dark shadow pass through his face and his wild and wooly looks pop out from time to time despite his normal thoughtless and bright face. ┬Ā Kim Seolhyun ŌĆō Gong Hye Won (a member of special task force at the National Police Agency) She is a passionate police officer who does not let anything get in her way. She became a police, defeating her parentsŌĆÖ fierce opposition. It was her spirit of disproving her familyŌĆÖs anachronistic idea that a girl should just be pretty and get married, but the reality is just cruel. She became a traffic cop just because she was a woman, but got to join a special task force after meeting the ŌĆ£cynical kingŌĆØ Do Jung Woo. ┬Ā Lee Chung Ah ŌĆō Jamie Layton (criminal profiler from FBI) She is a former FBI criminal profiler. When the shocking incident of sending a notice before committing murder shocks Korea, she joins the special task force at the National Police AgencyŌĆÖs request and begins to grasp the core of the case. It looks like everything is perfect with her, but the fact that she has no memory of her childhood is her weakness. And the more she unravels the truth behind the case with her guts, Do Jung Woo catches her eyes. ┬Ā Yoon Sun Woo ŌĆō Moon Jae Woong (MODU hacker) He lives inside the online world and eats ramen at the corner of the convenience store, but his true identity is a genius hacker that manipulates public opinion on KoreaŌĆÖs top portal, ŌĆ£MODU.ŌĆØ Jae Woong, who is friendless and a social misfit, canŌĆÖt stop thinking about Jamie Layton, the first person who showed interest in him.