The dandy prince Lin Yu unexpectedly swapped bodies with the bullied, frail ninth princess Xiao Liyue. Lin Yu was also bound to the empress system, which rotates every ten days. Living in the princess's body, he changed his cowardice, punished the palace servants, outsmarted the princess, exposed the concubines' conspiracy, and resolved the marriage crisis, which won the emperor's appreciation. After being granted the title of Princess Chenghua, she set out to become the empress step by step. Xiao Liyue, who entered the body of the prince, washed away her reputation as a playboy. She studied hard and practiced martial arts to win the county examination. She was determined to gain fame and revitalize the prince's palace. The two supported each other and worked hand in hand to deal with the many crises in the court and harem, and gradually fell in love with each other.
