A young girl who lives with her cruel stepmother and sister, accidentally meets 3 young and rich cousins who live a luxury life in a big mansion and is hired by the boys grandpa to look after their bad behavior.

A man named Shin Woo regrets letting his first love go ten years ago because he didn't have the courage to confess. However, he gets the chance to win her again when he travels back in time...

A love story of a cold city scholar Gyun Woo, who's known as "Joseon's national treasure", and the sassy princess Hye Myung in a Joseon Dynasty era.