The Princess Royal.

Because of political reasons, princess Li Rong and Pei Wenxuan got married at the age of 18. In the end they drifted further and further afar from each other. After 20 years of a loveless marriage, they were manipulated into turning against each other, leading to their deaths. However, they wake up back at 18, before their marriage, facing the hardest time of their lives. The two of them are given second change together, to save those around them.