Sensei Yumun started Taekwondo at 16 under Michael Tan Kim Chee. She proceeded to achieve 5th dan in Taekwondo and competed actively until a knee injury forced retirement at age 22. After reconstruction surgery, she attended her first referee course in Mentakab, Pahang in 1998 where she first met Shihan Michael Ding. During her National Referee examination (where she yelled until her tooth fillings came out), Shihan Michael prohibited her from sitting for the test as her then instructor failed to settle her annual membership fees.
Yumun waited patiently for Shihan Michael to open up a Taekwondo class so she could learn from him. After waiting 2 years, she finally decided to join his existing Kyokushin Karate class instead. Starting over from white belt , she was not well liked by the majority of seniors. Many (especially the males) tried to knock her out during kumite in the vain attempt to get her to quit. Fortunately Yumun has a fairly hard head and she came back for more.
Slowly but surely, she rose through the ranks and obtained Shodan. Yumun competed in various national level Taekwondo tournaments; a few Kyokushin All Japans; a British Open; and once even in Muay Thai.
Now, she focuses more on kobudo and teaching.