The Duo is swashbuckling tale of a bandit hero who fights for the people. Chun Doong is born into a noble family, but he's switched at birth with the son of peasants. Growing up poor and downtrodden, he gradually grows angry as he watches the oppression around him, and becomes a heroic outlaw. Meanwhile, Gwi Dong, the child he was switched with, grows up as a privileged nobleman, and becomes a head of the police. The two men, unconsciously living each other's lives, are total opposites-one stands for justice through the law, and the other seeks justice through crime. Fate has plans to reunite them, however, when they both fall for the same beautiful woman. A fusion sageuk-or historical drama-that combines action and romance in a fun blend, The Duo is an easy hit with audiences.