Su Wantang was transformed into the concubine of the prime minister's palace, and she was originally the "control group" of her sister Su Qingtang - her appearance, talent, knowledge, and marriage were all crushed. She is so cute that she doesn't hold grudges, but when she was poisoned while trying food for her eldest sister, she was saved by the yandere prince Xiao Chengyu who was on patrol incognito. Xiao Chengyu had long regarded her as a treasure, and often entered the prime minister's house in the name of curing drugs. While slapping her harsh stepmother Wang in the face, he secretly planned to reveal his identity as a "prince living among the people". Out of jealousy, Su Qingtang joined forces with the Wang family to set up a trap, but was exposed under Xiao Chengyu's every step of the way. When Xiao Chengyu stood in the golden palace as a prince, he was shocked to realize that the "little sugar cake" who saved his life was this cute girl who always stuffed candied fruits into his palms. The two went from protecting each other to falling in love, and finally worked together to resolve the crisis of the reserve, achieving a prosperous story of "the emperor and the empress are united".
