In the 1980s Hiroyuki Nakajo won multiple medals at the Asian Games and represented Japan at the Olympics in sports shooting. Nakajo competed at the 1982 Asian Games in New Delhi where he won silver in the 10 metres air rifle team event and bronze in both the 10 metres air rifle and the 50 metres standard rifle 3 positions team. Two years later he competed in the 50 metres prone small-bore rifle at the 1984 Los Angeles Olympics where he finished 17th. He returned to the Asian Games in Seoul in 1986 where he won bronze in the 10 metres air rifle team and the 50 metres small-bore rifle 3 positions team events. From 2000 to 2019 Nakajo worked as coach at the air rifle club at Eihoku High School.