Fans of WWE's Attitude Era will remember Yamaguchi as the leader of the Kaientai faction, which consisted of Japanese wrestlers. Kaientai's most famous feud was against Val Venis after Venis slept with Yamaguchi's wife in the storyline. At one point, Yamaguchi had threatened to cut off Venis' genitals.
Figure Four Online'sDave Meltzer noted Yamaguchi also built a name for himself outside of WWE through his work with Gong Magazine, a weekly wrestling magazine in Japan. WWE added that the 60-year-old was a referee and road agent for multiple promotions in Japan and at one time worked for WWE as an intermediary between the company and Japan.
According to Meltzer, Yamaguchi had a "serious stroke" in 2017.
Yamaguchi's brother, Shun, currently works for WWE as a Japanese-language announcer during pay-per-view broadcasts.