Set during the Tang Dynasty of China, Can't Buy Me Love tells the story of the Third Princess, Princess Chiu Yeung, of the Tang Emperor, who is beautiful but very unreasonable, and, as such, no one wants to marry her. The Kam family is the largest gold manufacturer in the grand capital Chang'an, but because they are deceived, the business runs into troubles. The second son of the Kam family Kam Tuo Luk has to marry the Third Princess to save the family business, because then they will have the right to manufacture gold pieces for the Tang Palace, the Third Princess only agreeing to the marriage because otherwise she would be married off to the Tibetan king Songtsän Gampo, as schemed by the evil Concubine Wei.

The Princess brings lots of servants to the Kam family after marrying Kam Tuo Luk, and constantly comes into conflict with the members of the Kam family. The Princess brings Szeto Ngan Ping, with her to the Kam family, who has been awarded "Best Servant" by the Concubine Dowager Chui and later became wife of Ding Yau Wai. The Princess originally decides to leave the house, but when she misunderstands that the Kam family speaks negatively of her, she stubbornly stays. Later, she and Kam Tuo Luk fall in love. When the Kam family is convicted of a capital offence, she divorces Kam Tuo Luk to secretly save the Kam family.