After graduating in 1968 Masatomo Taniguchi joined Nippon Kokan, playing for them in the Japanese Basketball League. Taniguchi was the league’s MVP twice and the top-scorer for his team in five consecutive seasons from 1971. In 1970 he represented Japan at the Asian Games in Bangkok where the team won the bronze medal. Two years later he played in the basketball tournament at the 1972 München Olympics. Despite Japan finishing 14th, Taniguchi finished as the highest point scorer in the tournament, scoring 191 points in nine games. Following his retirement in 1976 he went on to serve as the executive director of the Japan Basketball Association.