Keye Luke

Character: Shigeru Kawamura / Sunagawa / Toji (voice)

Aya Oyama

Character: Kiyo / woman outside hospital / female honeymooner (voice)

George Takei

Character: Dr. Kyuichiro Kashiwagi / Izeki / male honeymooner (voice)

Paul Frees

Character: Nishimura / Suda / Dr. Tanaka / Air Force officer / Kitahara (voice)

Marvin Miller

Character: Air Self-Defense Force commander / Air Force pilot / newsreader (voice)

James Yagi

Character: Osaki / Professor Minami / hotel manager / farmer (voice)

Jane Chang

Character: Otami (voice)

David Duncan

Character: Narrator

Haruo Nakajima

Character: Rodan / Meganulon (uncredited)

Kenji Sahara

Character: Shigeru Kawamura

Yumi Shirakawa

Character: Kiyo

Akihiko Hirata

Character: Dr. Kyuichiro Kashiwagi

Minosuke Yamada

Character: Osaki

Yoshibumi Tajima

Character: Izeki

Akio Kobori

Character: Nishimura