Sun was born on March 20, 1980 into the powerful Paik family; natives of Seoul. As a child, Sun was taught how to play the piano. On at least one occasion, she blamed the results of some mischief on a maid in order to avoid punishment. Later, Sun attended Seoul National University, majoring in Art History. When she returned without a husband, her mother arranged for her to meet a potential suitor, Jae Lee. The two hit it off until Jae Lee revealed that he planned on marrying an American woman. An upset Sun left him, only to quite literally bump into Jin-Soo Kwon (Daniel Dae Kim), her future husband. While Sun had doubts regarding her father's approval, she was surprised when Jin presented her with an engagement ring. They were wed in Korea, and at the reception, they were complimented by a Korean-speaking Jacob. Shortly after the wedding, however, Sun was approached by a woman claiming to be Jin's mother; she blackmailed Sun into paying her a large sum of money, with the threat of bringing shame upon the Paik family by revealing Jin to be the son of a fisherman and a prostitute. Sun asked her father for the money, but when she did not provide a reason, Mr. Paik assumed it was for Jin, and assigned him a new job until the debt was paid. Over time, Jin grew distant from Sun, and she planned on escaping her failing marriage. She began taking English lessons from Jae Lee, whose own plans had not worked out.