Shen Yu, a modern-day overworked office employee who hates the cutthroat work culture, dies suddenly after working overtime for three consecutive nights. She wakes up in the Great Yue Dynasty, having transmigrated into the body of an insignificant concubine-born daughter who has been forced to marry the tyrannical Regent, Xiao Xuance, in place of her legitimate elder sister. To avoid being killed, she deliberately slacks off and acts recklessly, hoping to provoke him into divorcing her so she can escape. Instead, she catches Xiao Xuance's attention. When he discovers that Shen Yu carries the life-saving jade pendant he gave away in his youth, he is moved by her straightforward and lively personality and becomes fiercely protective of his wife. As her legitimate elder sister, Concubine Liu, the Third Prince, and the Empress Dowager take turns framing her, Shen Yu uses her modern workplace savvy to overcome every crisis. From mutual suspicion to standing together through life and death, the two join forces to crush a conspiracy to usurp the throne. With the crisis over, Xiao Xuance surrenders his military authority and promises to love only Shen Yu for the rest of his life.