Joseon is in a state of disorder due to uprisings and a power struggle surrounding King Lee Hun. To avoid assassination, a clown named Ha Sun is brought to the palace to take the place of King Lee Hun. Ha Sun looks almost identical to King Lee Hun.
When Ha Sun was a child, his parents died during an epidemic. Ha Sun almost died from starvation around that time, but he was read moresaved by a group of clowns. Ha Sun grew up with the clowns and became one of them. During their performance, Ha Sun would play King Lee Hun due to their similar physical appearance. Now, Ha Sun is nervous that someone in the palace will find out he is not the real king. He falls for beautiful Queen Yoo So Woon.
~~The drama adaptation of "Masquerade", is a story that takes inspiration from "The Prince and the Pauper" by Mark Twain.
(Source: AsianWiki, HanCinema)