Yoshihiro Akiyama (秋山 成勲) (born July 29, 1975), also known as Sung Hoon Choo (추성훈), is a Japanese mixed martial artist and judoka. Akiyama won the gold medal at the 2001 Asian Championships for South Korea, and for Japan at the 2002 Asian Games. A fourth-generation Japanese of Korean descent, he acquired Japanese nationality in 2001. He is the former K-1 HERO’s Light Heavyweight Grand Prix Tournament Champion.