Masquerade

Amid national chaos and fear for his life, tyrannical King Gwang Hae orders his trusted councilor Heo Kyun to find a royal body double. He hires Ha Seon, a peasant mimic who bears a perfect resemblance to the King. When King Gwanghae collapses from a mysterious poison, Ha Seon reluctantly becomes a King. He must follow his conscience to save his country from collapse, avoid assassination, and pull off the biggest masquerade in history.
(Source: CJ Entertainment)