He had an unusual background for an actor: his formal education began in a kindergarten founded by the wartime-era Japanese Imperial Army and continued in a military academy which was Tokyo’s answer to West Point. Upon graduating from Tokyo University, Hirata confounded many family expectations of him by pursuing a career in acting.
His first roles in Even the Mighty Shed Tears (1953) and The Last Embrace (1953) brought him to the attention of director Ishiro Honda, who promptly cast Hirata first in his WW2 romance Farewell Rabaul Saraba Rabauru (1954) and then, later that year, in the role that would come to define Hirata’s career: the tormented, one-eyed scientist Daisuke Serizawa, who alone has figured out a way to destroy the monster Gojira Godzilla (1954). That movie made stars out of all of the younger actors who were fortunate enough to star in it, though Hirata tended more towards second leads and character parts. He was often called the best-known of all actors to appear in Gojira movies (he would turn up in six of the sequels), but this was due as much to his popularity with directors as with his exposure through the monster movies.
He was a favorite of directors Ishiro Honda, Jun Fukuda, Hiroshi Inagaki, and much beloved by virtually all the actors who knew him: honest and humorous, highly intellectual but never pretentious. He appeared in literally every kind of movie Toho Studios made, from the monster pictures to samurai dramas (including his one movie for Akira Kurosawa, Sanjuro (1962) to war dramas to comedies. Still, he remained identified most directly in the public’s mind with the original Gojira; his character Serizawa is among the best remembered and most admired in all Japanese films, both inside Japan and out. Hirata was chosen by Toho to announce the monster’s return in Godzilla 1985, and was tapped for a major role; but he died tragically of lung cancer before he could begin shooting.