He was affiliated with Nashville-area wrestling promoter Nick Gulas for most of his career. In Nashville, he was promoted as "the most hated wrestler of all time" and "the epitome of evil". Nick Gulas was notorious for supposedly underpaying his wrestlers, but Yamamoto and his trainee Jackie Fargo were notable exceptions. They were two of Gulas's best draws from the early 60's to the early 70's, but in addition to the money they generated, they were also reliable and loyal. Yamamoto showed his allegiance despite offers from other promoters, including an offer from his close friend and student Jerry Jarrett when he started promoting shows of his own.