Lee Chih-Kai was born in Yilan County, Taiwan. He started training as an artistic gymnast at six years old when he met his coach, Lin Yu-Shin. Lee joined the gymnastic team when he studied in Gong Jheng Elementary School in Luo-Dong Township. Lee was nicknamed “Market boy Kai” because he liked to perform his gymnastic skills in the traditional market where his parents worked. At the beginning of his career, Lee started practicing a difficult element named “Thomas Flairs”, which was commonly performed on the floor in gymnastics. Because of his coach’s suggestion, Lee moved the Thomas Flairs into his pommel horse routine when he studied in the middle school.