He is one of the few Japanese champions that lacked financial backing from large gyms or television companies, and he had to personally negotiate with opponents to land a shot at the world title.
He continued boxing at Nippon University, and fought in the 1984 Los Angeles Olympics while attending (he lost in the second round).
Hiranaka became the WBA's top-ranked fighter in the light welterweight division, but lack of financial support made it difficult for him to challenge the world title.
Hiranaka finally got his second chance in April 1992, fighting in Mexico City against Puerto Rican world champion, Edwin Rosario.
Despite making an epic entrance onto the world stage, Hiranaka lost his title after only five months to Morris East from the Philippines.