Mizunuma was born in Saitama on May 28, 1960. After graduating from Hosei University, he joined Japan Soccer League club Nissan Motors (later "Yokohama Marinos") in 1983. The club won 1983 and 1985 Emperor's Cup. From 1988 to 1990, the club won all three major title in Japan; Japan Soccer League, JSL Cup and Emperor's Cup for 2 years in a row. In 1990s, the club won 1990 JSL Cup, 1991 and 1992 Emperor's Cup. In Asia, the club won 1991–92 and 1992–93 Asian Cup Winners' Cup. In 1995 season, he retired after he played in opening game.