Gu Ping'an arrives in Qiantang to investigate an unsolved case left by his late father. There, he encounters Song Shirui, who is troubled by the "single tax" she has to pay. The two pretend to be a married couple and open a restaurant together. During their journey as business partners, they develop feelings for each other, overcome fierce competition in the restaurant industry, and uncover the criminal forces entrenched in Qiantang. Together, they bring justice to Gu Ping'an's father's unresolved case.