Kim was born on August 2nd, 1945 in Kaesong City. In July 1950, Kim was orphaned from the Korean war and taken in and adopted by his eventual boxing manager and trainer, Colonel Jodal Hyun. Under Hyun's guidance, Kim started boxing in high school.
Kim had an accomplished amateur boxing record of 108 matches, 108 victories. He turned pro at the age of 33 and quickly became the OPBF champion within 12 fights in 3 years, and impressive feat for a bantamweight boxer since age affects fighters in lower weight classes much earlier. It is said that two of his opponents were killed in the ring during his first 12 bouts. Before his match with Joe, him and his coach were planning to issue a challenge to the world champion Jose Mendoza, even going so far as to tell the media that's the fight they were training for, not Joe.
As a boxer, Kim maintains a very cool and conservative style in the ring. He selects his punches carefully and doesn't push himself to go for a knockout early, instead preferring to let his opponent miss and tire themselves out before getting a knockout in the later rounds. He carefully analyzes and observes his opponents and backed by his confidence carries out each fight with stone cold precision, earning him the nickname "The Human Computer".
~!Kim retired at the age of 36 with 13 wins, all by KO, and 1 knockout loss to Joe Yabuki who succeeded him as the OPBF champion. He retired as a result of his injuries sustained in his final match against Joe.!~
