Hiroshige began his training at Kyokushinkaikan So-Honbu Dojo in June of 1972. Three years later he entered Mas Oyama's Waka Jishi Ryo (Young Lions Dormitory) where he became Dormitory Chief responsible for overseeing the activities of younger uchi deshi. At the unheard-of late age of 28 Hiroshige began tournament fighting with his debut in the 8th All-Japan Tournament. After this tournament he supplemented his karate training with Ikken, and took 7th place in the next year's 9th All-Japan tournament. Hiroshige then went on to take 4th place in the 10th All-Japan tournament, and 5th place in the 11th All-Japan Tournament. In 1979 he represented Japan as a member of the 2nd World Open Karate Tournament team.
In June of 1978, Hiroshige founded the Jonan Branch of Mas Oyama's Kyokushinkaikan in Tokyo, and there, due to his original teaching style, emphasis on hard training, and special attention paid to special characteristics of each potential fighter, he made three successive world champions, Midori Kenji in 1991, Yamaki Kenji in 1995 and Tsukamoto Norichika in 1999. Since the World Tournament was only held once every four years, this means that Hiroshige's students remained world champions for 12 years. Additionally, Hiroshige made All-Japan champions, Kazumi Hajime and Takaku Masayoshi.
Hiroshige coached the Japanese Kyokushinkaikan World Cup team for the Paris competition in 1998, and the Japanese team for the 7th World Open Karate Tournament in 1999.
In December of 2002, Hiroshige left Kyokushinkaikan, and founded Kyokushin-kan together with Royama Hatsuo with the intention of reviving Kyokushin Karate to the status that it held during Mas Oyama's lifetime.