Youlan is the fifth among the twelve oirans in the brothel, because she met Situ Muyun, the king of Zhongnan, in the orchid sea. As a result, the prince desperately wanted her to be his princess.
For her, the prince went to the brothel to work as a handyman, served tea and water for others, and did not hesitate to work hard for a joke... He was a good man.
Watching "Butterfield Love", you know that time travel is not easy.