This was a novel set in ancient China. The male protagonist was called Shangguan Che, and the female protagonist was also surnamed Shangguan. They were cousins. The female lead was a princess and the male lead's father was the emperor. They had known each other since they were young and had become each other's closest companions after growing up. However, due to some political reasons, they were forced to live as brother and sister. They gradually discovered their feelings for each other, but the political struggle in the palace made them unable to be together. In the end, they chose to let go of everything and help each other through the difficulties together. This novel might have some romantic and touching plot, but it might also have some complicated political background.