Teiken Boxing Gym
In December 2002, Akihiko Honda who has been looking for excellent trainers who can bring out the boxers' ability all over the world, requested him to become a trainer of his Teiken Boxing Gym. Tanaka started to coach in Japan at times other than Barrera's training, and signed a deal with Teiken Boxing Gym in May 2003. While instructing Jorge Linares intensively, he made some other boxers spar with Barrera, or made them participate in his training camps. In Linares' first world title shot in Las Vegas, Nevada in July 2007, Tanaka served as the chief second among Rudy Pérez, Rudy Hernández and Kenny Adams. Just before the gong sounded, Tanaka tapped on his back saying that "Thanks for making me a second of the world champion. Let's go". Tanaka later told that he changed the plan during the fight and Linares neatly ran it since he was a superior boxer.