Elder princess Li Huai Yu dedicates all her efforts to assisting her brother, the young Emperor Li Huai Lin, in governing the country, but is framed for the murder of Sima and disrupting the order of the court and sentenced to death with a cup of poisonous wine. She survives, but with her appearance changed, and somehow assumes the identity of the fourth daughter of the Imperial Censor, Bai Zhu Ji. After getting a clear hold of the political situation, Li Huai Yu decides to make use of her new identity to investigate the Sima case. She intentionally gets close to the royal advisor Jiang Xuan Jin, who sent her the poisoned wine, but discovers that Jiang Xuan Jin is not the person who framed her and decides to work together with him to investigate the case. In the process of investigation, they also destroy the corrupted ways of the court. Jiang Xuan Jin puts aside his prejudice of Li Huai Yu and realizes that she is an upright person. They also fall in love with each other. (Source: DramaWiki) Adapted from the web novel "Spring Banquet" (春日宴) by Bai Lu Cheng Shuang (白鹭成双).