It tells the story of Dongfang Huaizhu and Wangquan Hongye, the leaders of two major families, the Dongfangs and the Wangquans. In a time when humans and demons are in conflict, they work together to stabilize the situation in order to revive the Unity Alliance. On the seventh day of the seventh month, at the Bamboo Pavilion by the Huai River, their fates intertwine like the sheaths of two swords, never to be separated. They pick up the most heartwarming promise and tell a story that has endured for generations.