Crown Prince Sajo Hyun (Park Ji-Hoon) has two different personalities. One is Sajo Hyun. While hiding his identity as the crown prince, he works as a fashion designer for a boutique store. He can’t get over the painful memory he got from his oppressive father, the king, while he was a child. His other personality is Ak-Hee (Park Ji-Hoon). He is an attractive man who can make people fall in love with him, but he is cursed that when he touches someone else, he feels extreme pain. These two personalities makes a deal to share their body for 3 days at a time.

Meanwhile, Yeon Wol (Hong Ye-Ji) was an only child and the successor of the Yeon Family, but her entire family was executed for her father committing treason. After that, she changed her name to Gye-Ra and joined an assassin group. One night, in order to kill the king and avenge her family’s deaths, she sneaks into the royal palace. Things don't go as planned and she falls into a trap. When she wakes up, she has become Crown Prince Sajo Hyun’s concubine and she doesn’t remember who she is. She faces Crown Prince Sajo Hyun and his different personality Ak-Hee.