Confidential Assignment is an action-comedy movie that follows the story of a detective from South Korea who teams up with a North Korean soldier to solve a case. The movie revolves around their cooperation despite the differences in their backgrounds and the tense inter-Korean relations. They have to work together and overcome obstacles including gun fights, car chases, and loss of trust to complete their confidential assignment.

In a global cooperative investigation, South Korean, North Korean, and American detectives join forces, each with their own motives. Rim Chul Ryung returns to South Korea to track down a dangerous secret criminal organization, teaming up with Kang Jin Tae, who wants to get back on the investigation team. Together, they face challenges and navigate inter-Korean relations.