A prince comes along to marry the king's daughter. However, the daughter is not happy. There is a mysterious knight who she had her eyes on, but this knight isn't who she thinks they are.

Kim Hyuna is the king's daughter. Her parents tried to raise her to be a good daughter and a good future queen, but their attempts failed. Hyuna is slightly weird, but is fun to be around.

Heo Gayoon is the knight in charge of Hyuna. She watches over her all day and makes sure the princess is safe and happy. Everyone believes that because she is a knight, she is a boy. Nobody questions her since she is one of the highest ranked knights in the kingdom.