Wealthy chaebol, Lee Ji-eun (Hong Soo-ah) falls in love with the poor Jang Sae-hoon and marries against their families' wishes. Ji-eun was engaged to Sae-hoon's family friend, Seo Jeong-in (Seo Ha-jun), but he was in a committed relationship with another woman. The couple was expecting a child despite the lack of approval from Jeong-in's father. Ji-eun and Sae-hoon eventually divorce, and Jeong-in later dies. After ten years, Ji-eun and Sae-hoon meet again but with swapped lifestyles. Once affluent, Ji-eun lost her fortune while Sae-hoon became a rich entrepreneur. Their changes in wealth allow them to view the world differently and understand each other leading to their reunification. However, they both have other love interests. Ji-eun meets Seo Jeong-min (Seo Ha-jun), heir to the Seorin Group and Jeong-in's twin brother, and they start going out while Sae-hoon is dating his girlfriend, Mi-ran. At the same time, Jeong-min's ambitious stepmother, Choi Myung-hwa, wants to hang on to Seorin Group at all costs. She is Mi-ran's mother but living under an assumed name and has not seen Mi-ran in years. Jeong-min dislikes Myung-hwa, and Seo Moon-soo (chairman of Seorin Group, Jeong-min's father, and Myung-hwa's husband) plans to remove her. The show ends with a series of legal cases against Seorin Group, ironically brought to court by Jeong-min himself after he tires of his father's controlling tendencies. Seo Moon-soo is angry at his only living son after Jeong-in's death. In the legal chaos, Moon-soo jettisons Myung-hwa but she kills him and stays with her daughter. Ji-eun and Jeong-min break up, and Ji-eun and Sae-hoon start to work together again.
