Seong Gi-hun is a chauffeur. He has dark hair and dark eyes. He lives in his residential neighbourhood town, Ssangmun-dong in Seoul in South Korea with his mother, Oh Mal-soon, to cope with owing ₩250 million to the bank and ₩160 million more to loan sharks. He has an ex-wife named Kang Eun-ji, who has custody of their daughter, Seong Ga-yeong. Gi-hun is a friendly, nice and talkative guy with a thoughtful nature, and cares for his family. He has a serious ludopathy, causing him to gamble.