[1] Outside of the Olympics, Hiroshima experienced much success on the Japanese marathon circuit.
[2] Between 1953 and 1959 he often registered within the world's top twenty fastest marathon runners of the year.
[3] He was a three-time winner of the Lake Biwa Marathon, with victories in 1955, 1957 and 1959.
[7] He also proved himself adept at the 20 kilometres distance when he won the Kashima Yutoku 20K in both 1955 and 1957.
[8] Although Hiroshima was largely focused on running in Japan throughout his career, he competed at the Boston Marathon in 1954 and just missed out on a podium place in fourth position.