However, Chun taught at the Yun Mu Kwan for only a few years prior to the break out of hostilities between North and South Korea, having disappeared during that conflict, the Korean War.
Eventually Jidokwan would be absorbed, along with most of the other original Korean "kwans," into the new national art which was ultimately named "taekwondo" and which developed a standardized approach to training and methods that differed in many ways from the older transplanted Japanese-sourced karate styles it had come from.
One variant evolved, however, in New York City where a Korean practitioner named Min Kyu Pai began teaching the style after emigrating to the United States in the 1950s.
His early efforts led to the introduction of the style to parts of Central America through one of his students, Francisco Miranda, who helped popularize karate in his native country of El Salvador.
[9][10] Pai had come to the United States at the age of twenty and, according to one of his successors, James Stewart, worked as a hospital orderly for a time to earn enough to survive while attending a local college.
Pai eventually distanced himself from the tournament world and turned inward, to the development of a synthesis of Chinese methods, as he found them in New York City, with the older Yun Mu Kwan he had brought with him from Korea.
By the early 1970s, Min Kyu Pai's teaching methods had changed so significantly that they ceased, in many ways, to resemble the older form of Yun Mu Kwan with which he had begun.
The most important influence on him at this time was Yang-style tai chi, a soft or internal Chinese martial art which was quite different from other forms of kung fu (among which it is categorized in China).
In the late 20th century, due to China's opening, the older Chen style of tai chi caught up with its younger sibling and became equally well-known, if not more so, at least in the martial arts community.
Min Pai, who trained in Yang style tai chi under Cheng Man-ch'ing, brought about marked changes in the methods he taught in his later years.
By 1973, Min Kyu Pai's martial art, except for its general karate format, was no longer recognizable as the older form of Yun Mu Kwan with its emphasis on Korean-style high kicking and the hard, direct and aggressive methods of classic Japanese Shotokan.
Despite the significant differences in the methods he had developed from those he had brought with him from his native Korea, Pai retained the Yun Mu Kwan name for most of his career, until some time after 1987 when he re-dubbed his style "Nabi Su" (meaning "butterfly hand" or "way"), a name he took from a form (a fixed practice routine, called "kata" by the Japanese and "hyung" or "poomse" in Korean) which he had developed in his later years to capture and crystallize the changes in combat methods he had embraced.