Watanabe was born in Nasu, Tochigi on June 4, 1953. After graduating from Nasu High School, he joined his local club Towa Real Estate in 1972. The club moved to Tokyo and was changed to "Fujita Industries" in 1975. The club won the Japan Soccer League champions in 1977, 1979 and 1981. The club also won 1977 and 1979 Emperor's Cup. He retired in 1983. He played 201 games and scored 34 goals in the league.