Sun Kwon is a survivor of the Oceanic Flight 815 crash and the wife of Jin Kwon. Her marriage was on the rocks -- through Jin was unaware of just how much so -- when the plane crashed en route from Sydney to L.A.Sun long before had a marriage arranged with a man named Jae Lee and, while the two got along well, he told her he planned to marry an American woman and their relationship ended. She would up seeing him regularly even after she was married to Jin. Sun was planning to leave Jin in Sydney just before the flight, but changed her mind and boarded the flight with him.Sun gives no indication as to whether she can speak English, and the other survivors assume she does not because it's clear that Jin doesn't. Sun resents Jin's overbearing attitude on the island as he berates her for her appearance and for bathing in the sea. He lashes out at her for leaving the top button on her blouse undone, which she then buttons in front of him and secretly unbuttons again when he's gone.Sun initially keeps very quiet and to herself, but she soon develops a bond with Michael and later with Kate. Sun maintains a garden on the island and becomes instrumental in helping Jack with some medical procedures and in helping get other survivors out of bad situations.Before the crash, Sun and Jin had difficulty conceiving a child and a doctor told them that she was infertile. This becomes a critical piece of information later.