What is the true identity of Xue Shangshu, a little suicide note writer given by the royal family?

Xue Shangshu's real identity in the Book of Letters is Chang Wang. On the surface, Xue Shangshu is Xiao Jinyu's gentle and loving teacher. In fact, he still has an unknown identity. Xue Shangshu's true identity is Chang Wang, the son of the late emperor. The reason why I hide myself deeply is to plot against myself and ascend to the throne. In order to achieve this goal, Xue Shangshu has painstakingly planned for decades.

At that time, Xue Rucheng escaped the fate of being killed by playing dead. After a makeover, he returned to Beijing and began a series of actions to regain the throne. Xue Rucheng originally wanted to use Xiao Jinyu to help him spread the rumor that Chang Wang was still alive, but Xiao Jinyu had seen through his strategy and did not become a pawn at his mercy.

Xue Rucheng had to use his people to start spreading rumors that Chang Wang was still alive in the imperial court. The reason for spreading such remarks is that he wants to get more people's support, and he also said that his actions will be officially launched. Although Xiao Jinyu is a student of Xue Rucheng, her IQ is much higher than that of this teacher, so Xue Rucheng regards Xiao Jinyu as a stumbling block on her way to the throne.

Xue Rucheng tried to kill Xiao Jinyu many times, but in fact he still had deep feelings for this student. At the end of the TV series, Xiao Jinyu actually discovered the teacher's problem long ago, but he still wanted to give the teacher a chance to turn over a new leaf, so he never exposed it in public. However, Xue Rucheng was obsessed with the throne and eventually paid a heavy price for his evil deeds.