Greg began training in Ninjutsu with Stephen Hayes in 1981. Prior to and concurrent with this he trained in several schools and styles including; Aikido, Tae Kwon Do and Washin Ryu Karate do with world-famous Karate Master, Hidy Ochiai. In 1983 he made the first of many trips to Japan, attending the first International Ninjutsu Taikai (training festival) held at Yumoa Mura.

In the Spring of 1985 Greg moved to Japan to immerse himself in long-term, intensive training with Dr Hatsumi and the senior instructors of the Bujinkan. Those who were involved at the time know that the eighties saw a veritable explosion of interest in the art, with countless people traveling to Noda city for one or two-week visits. In those early years, before and as the Ninja Boom was reaching it's peak, Greg was one of only two Americans living in Japan specifically to train with the Grandmaster. During that time he became one of the first Americans/Foreigners and the first from the Northeast to receive Dan (black-belt) ranking in the art. He was also one of the first to pass the Godan (5th-degree) test in the Hombu Dojo. While the resident Gaijin (foreign) community had grown by the time Greg returned to America, there was still only a small handful that had made the commitment to live and train in Japan. To this day he is one of the only instructors living in North America to have lived and trained with Dr Hatsumi in Japan.

Greg returned to the U.S. in the summer of 1989 and began teaching a small group in his hometown of Wallingford, Connecticut. He has taught seminars and workshops around the U.S. and in Canada, teaching the art as he learned it in Japan and helping to correct misimpressions about the art, as well as many of it's teachers and practitioners. Greg continues to update his training as often as possible, traveling back to Japan, attending Tai Kai and hosting visits from some of the senior and most knowledgeable practitioners from Japan.