There is such a legend: It is said that a long time ago, a noble prince met an ordinary girl by chance. They fell in love and got married. However, during a misunderstanding, the girl disappeared because she was too sad. The prince searched many places but there was no news about the girl. Finally, he met an accident in a cold winter and died. On the day of the burial, the girl appeared. She cried very sadly, hit the wall on the spot and showed affection, and the blood flowed down her forehead to a piece of white jade...