Chang Ge Xing. Chang An in the Tang Dynasty of China (618–907): The demon star is passing through the sky, the Tang Dynasty is nearing calamity. Princess Yongning is forced to flee the castle after her family has been killed. Because she's young, she's able to go for a boy and become famous as a great military strategist. On her journey, she makes trusted allies with her abilities as well as fearsome enemies, aiming to protect the Tang Dynasty and exact vengeance.