Yoojun was born in Korea, and came to NZ in 2003. Graduated New Zealand College of Chiropractic in 2012 and started practicing as a Chiropractor in January 2013. In 2014 he started CrossFit to improve his fitness. Since then he became addicted, not only because CrossFit is fun, but also because he has learned more about what is going on inside the body, how it should move, and how it should not move. That helped with his profession as a Chiropractor and gave him the drive to do more research and study about the biomechanics of the human body.
Yoojun completed the CrossFit Level 1 Trainer (CF-L1) in 2017, and while currently practicing as a Chiropractor, Yoojun has joined the CFAK team as an Intern Coach.