- Bats Right, Throws Right
- Height 6' 0", Weight 160 lb.
- High School Takasago High School
- Born July 28, 1934 in Hyōgo Prefecture, Japan
In the history of Nippon Professional Baseball (through 2008), Masaaki Koyama ranks third in wins (320), strikeouts (3,159), innings pitched (4899), and shutouts (74). He was selected for eleven All-Star teams and won a Sawamura Award in 1962. In that year, Koyama had 13 shutouts including five in a row on his way to a 27-11 record with a 1.66 ERA. He is the son-in-law of Saburo Miyatake.
Koyama was inducted into the Japanese Baseball Hall of Fame in 2001.