Chang grew up in South Korea and moved to California in 1981 with his wife.
He and his wife, Jin Sook (Hangul: 진숙), opened a 900-square foot clothing store then named Fashion 21 in 1984 in Highland Park, Los Angeles with only $11,000 in savings. The store took off, and as they expanded to other locations the store's name was changed to Forever 21. The number of stores grew to 600, with 30,000 employees by 2015. The company has remained a family operation. Forbes in 2012 estimated Chang and his wife's net worth to be $4 billion.