Shihan Koh studied directly under Soke Teruo Hayashi and maintains a close relationship with the Hayashi-ha Board of Directors. Outside of Japan, he is Hayashi-ha’s longest-serving regional leader, having joined Hayashi-ha Shitoryukai in 1979. Prior to this, he trained under Sensei Clement Soo, the Soke and founder of Goshinryu Karate Malaysia, where he studied Shotokan, Keshin-Kan, and several Chinese martial arts systems for over 12 years.

Shihan Koh is renowned for his dynamic kicking ability and was a highly successful competitor in his youth. In 1970, he won the Malaysian Championships and was selected to represent Malaysia at the 2nd WUKO World Championships in Paris. His technical precision and athletic ability distinguished him as a leading figure in the competitive arena.

Today, Shihan Koh serves as the Australian Head of Style for Hayashi-ha Shitoryukai. He personally mentored Sensei Luke to the rank of 4th Dan and continues to lead the style across the Pacific region. Shihan Koh is widely respected as a technical master of Karatedo, carrying forward the rich traditions and teachings of Soke Hayashi.