Kim Sun-a was born in Daegu in 1975.[2] She is the eldest of three siblings, and has a younger brother and sister.[1] When Kim was in middle school, her family immigrated to Japan, and she spent much of her adolescence in Chōfu, Tokyo, where she learned to speak Japanese fluently.[3]
In 1993, Kim enrolled at Ball State University in Indiana, United States as a Piano major (she also became fluent in English).