Kim Je-ha, also known as K2, is a former mercenary soldier for the PMC Blackstone. While stationed in Iraq, he is framed for the murder of his lover, Raniya, and becomes a fugitive. Je-ha escapes to South Korea, where he is offered a job as a bodyguard by Choi Yoo-jin, the owner of JSS Security Company and the wife of a presidential candidate¹. He accepts the job to gain resources for his revenge against another presidential candidate, Park Kwan-soo, who ordered Raniya's killing. Je-ha is assigned to protect Go An-na, the secret daughter of Choi Yoo-jin's husband, and they develop a close bond. Throughout the series, Je-ha navigates complex political and personal conflicts, ultimately seeking justice and clearing his name.