Bai Xiangyi, a talented actress, is unexpectedly transported to an ancient world, becoming the concubine of Emperor Xuan Cheng with a system that allows her to romance anyone but the emperor. After meeting him disguised as a musician during a visit to a brothel, they form a friendship outside the palace. However, a glitch causes the emperor from her former life to seal away all memories of her in a river lantern, sending her back to the modern world. Meanwhile, Lu Xun, seeking revenge, assumes the identity of Chu Hang and forces Bai Xiangyi into a marriage agreement, only to unexpectedly fall for her as they navigate their complicated relationship.