A story about the love between Lin Chengyou, the son of King Cheng, and Teng Yuyi, the daughter of Jiangmen, involving past and present. Teng Yuyi was killed by a traitor, and when she woke up, she found that she had returned to the year before she was killed. Her cousin was not dead, her grandfather was still alive, and she accidentally obtained a "Xiaoya Sword" that can slay demons. With the help of this divine sword, Teng Yuyi embarked on the road of finding the truth. As a result, because of an encounter, she formed a relationship with Prince Cheng.