Keye Luke

Shigeru Kawamura / Sunagawa / Toji (voice)

George Takei

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

Paul Frees

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

Marvin Miller

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

James Yagi

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

Haruo Nakajima

Rodan / Meganulon (uncredited)

Kenji Sahara

Shigeru Kawamura

Yumi Shirakawa

Kiyo

Akihiko Hirata

Dr. Kyuichiro Kashiwagi

Minosuke Yamada

Osaki