His introduction to martial arts came through Kung Fu instructors Jack Chin and James Lore, who trained him for five years.

[1] He underwent kendo training under Larry Nakamura, Shigeo Kimura and Masatoshi Tagawa for five years and achieved the rank of ni-dan.

He was introduced to Yoshinkan Aikido at college where he joined a club led by Takeshi Kimeda, and would train under him for over a decade.

On March 30, 1986, he traveled to Japan to train at the Yoshinkan hombu dojo with an introduction letter from Kimeda and gifts for the instructors and uchi deshi as is customary.

Robert Mustard attained the rank of Nana-dan (7th degree black belt) in December 2006, and was awarded the title of Shihan in August 2011.