him to write a brief obituary on Choi that appeared in the April 1987 issue. Doju Chang died in his sleep on February 23, 2018 at the age of 77 as a result of Hypertensive Cardiovascular Disease. Students Many people have claimed to be students of Choi Yong-sool, and it is often hard to verify whether or not these claims are valid. This is a list of people who were long time students of Choi. Chinil Chang (the second direct lineage Grandmaster was awarded the only 10th Dan in Hapkido and the title of second direct lineage Doju by Dojunim Choi on January 15, 1985.) Seo Bok-Seob (; Choi's first student in 1946) Ji Han-Jae (; student #14 of Choi in 1955, Founder of the Korea Hapkido Association and Sin Moo Hapkido, and Sung Moo Kwan in Andong) Kwon Tae-Man (; First founder of a hapkido dojang in Incheon) Kim Yong-Jin (; Founder of the Ulchi Kwan) Myung Jae-Nam (; Founder of Hankido and Hankumdo) Oh Se-Lim (; former president of Korea Hapkido Federation) Myung Kwang-Sik (; Founder of the World Hapkido Federation) Kim Moo-Hong (; Choi's student in 1955, Founder of the Korean Hapkido Association and Shin Moo Kwan in Daegu) Kim Jung-Soo (; still teaching in Daegu) Won Kwang-Hwa (; Founder of the Moo Sool Kwan) Lim Hyun-Soo (; He was promoted to 9th Dan (highest dan in Hapki Yu Kwon Sul before dojunim's death) by Choi Yong-Sool. In 1974, he founded Jung Ki Kwan and later created a system of Jungki Hapkido and Chungsuk Kuhapdo) Moon Jong-Won (; Choi's student in 1955, Founder of Won Moo Kwan in Busan) Kim Jeong-Yoon (; Secretary General of the Kido Association and founder of Han Pul) Seo In-Sun(;) Yoo Byung-Don (; Han Kuk Jeong Dong Hapkido, Orthodox Hapkido) Han Bong-soo; (author, notable movie consultant and actor) Michael Wollmershauser; founder of American Hapkido Association until Dec. 8, 2002 See also Korean martial arts Daitō-ryū Aiki-jūjutsu Aiki (martial arts principle) Aikido References Further reading Kim, He-Young. Hapkido II. Andrew Jackson Press, Baton Rouge, Louisiana 1994. Kimm, He-Young. "History of Korea and Hapkido". Hando Press, Baton Rouge, Louisiana 2008. Myung, Kwang-Sik. Korean Hapkido; Ancient Art of Masters. World Hapkido Federation, Los Angeles, California 1976. Tedeschi, Marc. "Hapkido: Traditions, Philosophy, Technique". Weatherhill, Boston, Massachusetts 2000. External links Hapkidowon (World Hapkido Headquarters) The Korea Hapkido Federation – Official Website Jung Ki Kwan Martial arts school