In 1962, when Hiraki played for Furukawa Electric, he became a playing manager as Ken Naganuma successor for the club and managed until 1965. He also served an assistant coach for Japan national team and a manager for Japan U-20 national team. In 1968, he participated as a coach in 1968 Summer Olympics in Mexico City and Japan team won Bronze Medal. In 2018, this team was selected Japan Football Hall of Fame. In 1992, he signed with Nagoya Grampus Eight joined new league J1 League and he managed until 1993.