Martin Hisao Tanaka was an American professional wrestler better known as Duke Keomuka. He is the father of wrestler Pat Tanaka and referee Jimmy Tanaka.

Because he was a Japanese American in California during World War II, Tanaka was interned at Manzanar.

In the 1950s, Keomuka formed a very successful tag team with Hiro Matsuda. Keomuka was also a top wrestler in the 1950s and the 1960s while competing in Texas before settling in Florida.

Keomuka died on June 30, 1991 at the age of 70. His son was scheduled for a match teaming up with Paul Diamond (who at the time worked as Kato of the Orient Express tag team) to take on Haku and The Barbarian but didn't arrive as his father died the day before the match, so his manager Mr. Fuji took his place.