From Seoul South Korea, Koo is the ultimate tennis professional and truly one of the hardest-working people in the tennis industry. He has been teaching tennis and stringing racquets for 34 years and estimates he has over 185,000 hours of on-court tennis lessons. He has invested heavily in his personal development by traveling the world to attend various events, including the IART Symposium (2009, 2012, & 2015) and many USPTA and PTR annual conferences. He is a USPTA Elite Professional, USPTR Pro 1, KPTA Pro 1, and a USRSA MRT. He is also a certified Etcheberry trainer and served on the Davis Cup stringing team in 2009 for Korea and China in ChunCheon Korea and for the WTA Tour Korea Open for 3 years in Seoul, South Korea (2007, 2008 & 2010)
