In March 1954, when Hiraki was a Kwansei Gakuin University student, he was selected Japan national team for 1954 World Cup qualification. At this qualification, on March 14, he debuted against South Korea. In 1956, he was selected Japan for 1956 Summer Olympics in Melbourne. He also played at 1954, 1958 and 1962 Asian Games. In 1964, he was selected Japan as captain for 1964 Summer Olympics in Tokyo. However, he could not play for injury. After 1964 Summer Olympics, he retired from national team. He played 30 games and scored 1 goal for Japan until 1962.