Lee emerged onto the world stage at the 2001 East Asian Games in Osaka, Japan, where she won a silver medal in the 63-kg division, losing the final by a "yusei" victory to Chinese judoka and 2000 Olympic silver medalist Li Shufang. This was followed by a share of bronze medal with Russia's Anna Saraeva in the similar category at the Summer Universiade in Beijing, China. As Japan hosted the 2003 World Judo Championships in Osaka, Lee finished in fifth place after losing the bronze medal match to Germany's Anna von Harnier.