Mu Changqing, the eldest son of Mu, and Shangguan Wan, the daughter of the Shangguan family, had been engaged in a child-marriage since childhood. It was originally a match made in heaven, but they didn't want the Shangguan family to fall due to sudden changes. Shangguan Wan married into the Mu family in order to find out the truth. The two worked together to find out the truth and gradually fell in love with each other, and became involved in the battle for the crown prince.
Purpose: Marriage first, love later