Yun is one of the early Taekwondo instructors, a contemporary of martial art Grandmasters Nam Tae Hi, Sang Kyu Shim, Jung Won Sun, Chang Gedo and Kim Il Woong.

[5] His early education included training in Hwang Kee's martial art of Tang Soo Do Moo Duk Kwan under the tutelage of Oh Sae Joon.

[1] Subsequently, he twice won the Tang Soo National Championships of Korea thus gaining the attention of Sang Kyu Shim.

From Choi, Yun would learn Taekwon-Do along with Cha Soo Young, Moon Ku Baek, and Jung Joong Sun.

[1] There Yun began to learn and instruct in the International Taekwon-Do Federation (ITF) style of taekwondo.