Kim began skating at the age of 6. Her coach at the time, Ryu Jong-hyun, strongly suggested to Kim's mother that Kim should continue to skate, predicting that she would become a world-class figure skater in the future. In a 2011 interview, she gave credit to her coaches for noticing her aptness for skating, stating, "My coaches have told me my muscles and body structure are perfect for skating. I was born with a good instrument, maybe more so than the talent. I was lucky my coaches noticed early on and helped me develop that. A lot of people don't know they are born that way." During her junior years, South Korea had limited facilities for figure skaters. Describing training conditions for competitive figure skaters, Kim said in an October 2010 interview with CNN, "During my early skating years, there were not many ice rinks in Korea and even the few rinks that existed, most of them were public. Even now, when athletes want to practice, they have to use the rink very early [in the] morning or late at night. Also, as there aren't enough ice rinks to facilitate all the figure skating teams, skaters often have to train in different rinks from day to day. Furthermore, as most rinks are too cold, there is always high possibility of injury." As proper skate shops were also lacking, Kim frequently had to wear ill-fitting skates in her teenage years, making it hard for her to balance and resulting in many injuries. In 2002, Kim competed internationally for the first time at the Triglav Trophy in Slovenia, where she won the gold medal in the novice competition. A year later, at age 12, she won the senior title at the South Korean Championships, becoming the youngest skater ever to win that title. She won her second international competition at the Golden Bear of Zagreb, a novice competition. She continued her reign as the South Korean champion in between 2003 and 2005.