Career
Kim Yoon-Sang began his study of Hapkido in the early 1960s under Master Chang Gedo, eventually reaching a grade of 5th Dan within the of Korea Hapkido Association. Thereafter Kim and Lee frequently travelled to Daegu to receive private lessons from Choi first at his school and then after it closed in 1976 in any available space. At the request of Choi Yong-Sool, Kim and Lee opened up a school for training (see: dojang) in their hometown of Geumsan in 1978.
In 1980 the school was named the Yong Sool Kwan (Hangul: 용술관) and Kim was appointed director of the school.
After the establishing of this training facility Choi Yong-Sool often came to teach at the school and Kim and Lee continued to travel to Daegu to train with their master. Established the Yong Sool Kwan in 1980.
Was awarded with a 9th degree black belt by Choi through the of Korea Hapkido Association in 1986. Compiled photographic records of Choi Yong-Sool performing techniques.
Renamed their system Hapki yusul to differentiate what they did from other hapkido groups.
Erected a special headstone for the grave of Choi Yong-Sool in 2000. Hosted a memorial of Choi Yong-Sool"s death in 2006 and 2011 which was attended by students from all over the world. Taught at several seminars in Germany, Australia England and Italy, February 2008.