Jiddung

Ryu Kang-Min is a member of the massive killer organization 'Batala.' This is a place from which there is no escape once you enter. Then one day, he receives a special commission in exchange for 'freedom.' The mission is to kill a 'target located in Korea.' Ryu returns to Korea for his freedom and, as a warm-up, eliminates the organization's 'traitor' first. Having completed his brief warm-up, he begins the mission in earnest... (Source: Naver, edited)