Dou Pihai and his sister, Dou Tuwei, make a living by selling swords and wine. Tuwei steals a sword from a customer and gives it to her brother, who makes some changes to it and puts it on sale.
Three years earlier, Tuwei falls in love with crown prince Zhu Erkui and gives him a sword. After ascending to the throne, the crown prince’s brother, Zhu Yunwen, visits the Dous’ store during an informal inspection tour. He rescues the brother and sister and brings them to the imperial palace. Erkui returns to the palace from a trip and is infuriated by the thought that his brother has usurped his throne and taken his love. The Empress Dowager wants to have Erkui executed. To save his brother, Yunwen deliberately insults him and forces him into exile.
Erkui attacks the state of Yan, and, after some twists and turns, marries the princess and becomes king of Yan. He leads his troops south, massacring civilians and laying waste to the land. After he finally procures the imperial seal, Erkui orders his brother to surrender his love, Tuwei. To save the people, Tuwei pretends to comply, though she ends up drugging Erkui with laced wine, stealing his sword and token of authority, and dismissing his troops.Erkui is later defeated while fighting Pihai, and Tuwei persuades him to commit suicide so as to show remorse for the violence and pain he has inflicted on the citizens. Both Tuwei andErkui commit suicide and are buried together east of the Jinchuan Bridge. Their story has been celebrated ever since.