he was born in suwon, gyeonggi-do, and moved to daejeon when he was a primary school student, where he was an inline speed skater. he began training in judo when he was 14 years old, and trained in taekwondo and hapkido together in his late teens for his interest in martial arts. and later kim began to practice judo professionally at yong-in university, which led him to reignite his mma career. kim began training at wajyutsu keisyukai, a renowned japanese gym frequented by a number of top japanese fighters. as one of the largest members of the gym, kim became a regular sparring partner of middleweight yushin okami. at this time he competed in judo and sambo. he served in the republic of korea marine corps in 2001 for his mandatory service. later he became a fighter for spirit mc, but declared his retirement in 2004 due to economic reasons. he mentioned during law of the jungle that before spending four months in auckland, new zealand working in 3 concurrent part-time roles (kitchenhand and sashimi chef/"poissonnier", bricklayer and construction labourer). his job situation never improved upon returning to korea, until his parents finally allowed him to train again. he trains with busan team mad since 2007. he teaches self defence classes. one of his students include hani of korean girl group exid.