Mikijirō Hira was a distinguished Japanese actor whose career spanned six decades, beginning in the mid-1950s. While he was primarily celebrated for his extensive work on stage and in live-action film and television, he also contributed to several notable anime productions as a voice actor. He was born on November 21, 1933, in Hiroshima Prefecture and passed away on October 23, 2016. His career in voice acting, though not as extensive as his on-screen work, included roles in some of the most historically significant animated films.

One of his most acclaimed voice roles came early in his career, when he voiced Grunwald the Demon of Ice in Isao Takahata's 1968 landmark film, The Great Adventure of Horus, Prince of the Sun. In this fantasy adventure, Hira provided the voice for the central antagonist, a powerful ice devil who threatens a northern village. The film is now recognized as a pivotal work in the history of Japanese animation, and Hira's performance contributed to its enduring legacy.

Decades later, he returned to voice acting for the 2012 animated film The Tibetan Dog, in which he voiced the character Tenzing as an adult. His filmography also includes a voice role as King Kashekim Nedakh in the Japanese dub of Disney's Atlantis: The Lost Empire. His live-action roles, such as Yasumasa Hirai in the film Doomed Megalopolis (also known as Tokyo: The Last Megalopolis) and Marquis Ōgawara in Rampo, are sometimes referenced in discussions of his genre work, though these are not voice acting roles.

Beyond his voice work, Hira was a towering figure in Japanese theater and cinema. He was a founding member of the Geidan Studio 68 and later worked extensively with the Gekidan Shiki theatre company. He gained widespread fame for his role in the television series Three Outlaw Samurai and was renowned for his powerful performances in Shakespearean plays, including acclaimed portrayals of Macbeth and King Lear. In 2005, he was appointed to the Order of the Rising Sun, 4th Class, for his contributions to the arts. Hira was married to actress Yoshiko Sakuma from 1970 to 1984, and his son, Takehiro Hira, is also an actor. He remained active in his profession until his death in 2016.