An ordinary woman, Su Ning'er, was forced to marry the cold-faced prince Yuqi because she looked very similar to the eldest princess. A decree broke her peaceful life. On their wedding night, facing Yu Qi's cold eyes and distant attitude, she knew full well that this marriage began with deception and exploitation. In the palace, the side concubines were making things difficult and the servants were scornful. The palace banquet was even more dangerous. She carefully played the role of "eldest princess", but when she got along with Yu Qi, she caught a glimpse of warmth under his cold appearance.
As the two experienced dangers in the suburbs and talked under the moon, feelings quietly grew in the undercurrent. However, the frame-up of the concubine and the news of the eldest princess made the identity crisis pressing. When Ning'er confessed the truth that she was a substitute, Yu Qi felt a mixture of love and hate in her heart. She finally recognized her inner choice and firmly guarded this unexpected love. They worked together to resist the pressure of the royal family, experienced court turmoil and life and death tests, started a marriage as a substitute, and finally tempered their true emotions in the wind and rain. Ning'er won recognition with her wisdom and kindness, and stood side by side with Yu Qi in the center of power. Together they wrote a legend from a substitute princess to a beloved concubine, and finally took her hand and spent a peaceful life together.
