Eighteen years ago, a child was left at the rich merchant's doorstep. Thus, Jae Yeong grew up as his younger son. Naive and pure hearted compared to his older step brother, he was often used by him. That changes when Jae Yeong find out about methods his family uses to keep officials on their side. After leaving home he joins Dong Hui and her father who is also a merchant and even meets his mother. He gets pulled into the politics world, where fight over the throne begins, with his brother supporting opposite side.