The night the future crown prince is born, a twin sister unexpectedly was also born but because of the King's decree to kill the new princess, the crown queen acts fast to make the baby girl pretend to be dead.
Years later, the princling crosses paths with his look-a-like and took advantage of the identical looks to sneak out momentarily. When court maid Dam-i fulfills her duty to the princling, she encounters Jung Ji Un, who is captivated by her and slowly becomes her friend. But of course as all ill-fated drama goes, the twins do another switch and because Dam-i was not meant to exist, the actual prince gets murdered in her disguise, leaving imposter prince Dam-i to fast track her mannerisms as prince Lee Hwi.
10 years later, during a royal hunt, physician Jung Ji Un is desperate to find herbs to save his Samgaebang clinic and shop assistant, but instead crosses paths with prince Lee Hwi while trying to hide her identity from tending to her wounds from a murder attempt. Lucky for both, they leave the scene unscathed and vouch to never cross paths again for the sake of the prince's true identity, or so they thought.
Like the butterfly affect, Prince Lee Hwi's feminane features and sometimes her actions start rumours around town thanks to Prince Changwon, the uncle with evil intensions and bad temper. Situations also didn't help when Jung Ji Un is appointed tutor to the Crown Prince, this opening unfulfilled feelings from the past.
Watch as Dam-i, or rather fake prince lee hwi survive the royal games, whilst trying to keep her affection towards Tutor Jung at bay.