Yamaguchi served as an assistant swimming coach at DePauw University for the last three years. The Tigers won the Southern Collegiate Athletic Conference in each of those three seasons while the coaching staff was named the SCAC Staff of the Year in 2007 -08 and 2009-10.
He also served as an aquatic staff member, student intern and team assistant for The Ohio State University men's varsity swimming team from 2004-07. The Buckeyes finished inside the top-30 at the NCAA National Championships all three years, posted a 10-1 record in '05 and turned out three All-Americans during that stretch.
Outside of coaching swimming, Yamaguchi is heavily involved in triathlons as has served as a coach at various professional levels over the last four years. He developed his own elite triathlon program that helps individuals interested in the sport by offering coaching analysis.
In July '08, he was assisant coach for the USA National Triathlon team at the Kitzbuhel International Triathlon Union World Cup. He has also served an assistant coach at the Hyvee World Cup (July '07), USAT Youth National Championship (August '06), Olympic Training Center in Chula Vista, Calif. (Februray and March '07) and has volunteered at the USAT Level I Coaching Certification clinic hosted by the USAT National Congress.
While at Ohio State, Yamaguchi served as the head coach of the triathlon club for one year. He created and managed training programs and became a USA Triathlon Level I Coach.
Yamaguchi also has a background in distance running as he was an assisant coach for the Hilliard Davidson High School boy's and girl's cross country teams (2004-05) and has been a coach/camp counselor at the Running School in White Lake, N.Y. since August 2004.
Yamaguchi graduated with his bachelor's degree from OSU in school and physical activity and educational services with a concentration in coaching and sports management in 2006. He also received his master's degree in physical education with a concentration in coaching from Indiana State University in August of 2010.