Sun-Hwa Kwon, better known simply as "Sun", is a fictional character on the ABC television series Lost played by Yunjin Kim.

An upset Sun left him, only to quite literally bump into Jin-Soo Kwon (Daniel Dae Kim), her future husband.

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.

During preparations for a business trip, with Jin, to Sydney and Los Angeles; Sun spoke privately with a woman acting as an interior decorator.

She was given instructions to leave Jin at the Sydney airport at 11:15 precisely; a car would be waiting outside the Oceanic Airlines gate and she was to maintain a low profile.

A single moment of tenderness from Jin, however, caused her to change her mind, and she decided to accompany him to Los Angeles.

Sun accidentally spilled coffee on Jin and after he left to clean himself off; she listened to the snide remarks of a couple seated a few tables away.

Sun approaches Michael in the jungle and, to his surprise, explains about the watch in English, asking him to keep her bilingualism a secret.

Later, Sun helps move the fallen rocks after Jack is caught in a cave in, and is almost volunteered to crawl through the narrow tunnel to save him by Jin.

When Shannon suffers a near-fatal asthma attack, Sun asks Michael to gather some eucalyptus plants, in order for her to make an herbal remedy for her.

Moments before departing, Sun writes Jin a phrasebook, containing English words written in Korean phonetics.

When the two learn of Michael's sudden departure to look for Walt, Sun refuses to allow Jin to help, reminding him that she is his wife.

Following Jack's success in contacting the freighter, Sun and Claire tend to Aaron shortly before heading back to the beach with the majority of the group.

When Sayid returns to begin ferrying people back to the freighter, Juliet states Sun should be the first to go as she is pregnant and as Aaron is in her care.

When they reach the boat, Sun is shocked to see Michael; their conversation is cut short when masses of C4 are found.

Amid chaos, Sun is forced onto the helicopter, and as it becomes airborne, she sees Jin running on deck, waving his hands frantically.

The six survivors of Oceanic 815, Lapidus, and Desmond take refuge on a raft, and soon they are spotted by Penelope Widmore's rescue ship.

Shortly after arriving home in Korea, Sun buys a majority share of her father's company with part of the Oceanic settlement that she received, and tells him that she holds him as one of two people responsible for Jin's death (the second person being Ben, as revealed in Season 5.)

Sun's quest for vengeance led her from Korea to Los Angeles, where a chance encounter with Charles Widmore turned contentious.

From the shadows of her car, Sun observed Kate, Hurley and the others deliberating over Aaron's fate.

Ben produced Jin's wedding ring as proof – Locke had safeguarded it to prevent Sun's return, shielding her from danger.

Under the enigmatic Ms. Hawking's guidance, they discovered an ancient "island tracker" machine pinpointing a narrow window between L.A. and Guam.

Boarding a fateful flight with Jack, Kate, Hurley, Sayid and Ben, Sun was enveloped by an ethereal glow.

The plane vanished, leaving fate uncertain – had they bridged time and space to reclaim their island destiny?

They all decide to destroy the Ajira Airways plane to prevent the Man in Black from escaping, but after a series of disagreements between Richard and Hurley, the group split; Ben, Miles, and Richard will search for more explosives, while the rest will go talk with the Man in Black.

Jack, Hurley, Sun, and Lapidus then run off to join Sawyer and Kate at the docks, hoping to abandon the Man in Black and seek refuge at Hydra Island with Charles Widmore's people.

Meeting with Sayid, they make their way to the Ajira flight, but the Man in Black claims that if they are to escape the Island, they should take Widmore's submarine.

At the dock, however, Widmore's men engage in a gunfight with them, forcing the submarine to leave Claire and the Man in Black behind.

As the submarine slowly floods, Sun begs Jin to leave her, but he insists on staying, telling her in Korean that they will never be apart again.