Hiroshi Masuda was a talented all-round sportsman who swam, played rugby, and competed in track and field athletics. In the latter Masuda won four Japanese titles and represented his country at the Olympics. In 1919 he became the national champion in the shot put and the javelin and won a second javelin title in 1921. The following year he won the decathlon title at the Japanese athletics championships. Masuda competed in the pentathlon at the 1920 Antwerpen Olympics but was forced to withdraw after two events due to an injury.