Astronauts Glenn and Fuji investigate Planet X and encounter mysterious aliens known as the Xiliens, who ask Earth's people to help save their world from "Monster Zero". In exchange for borrowing Godzilla and Rodan, the Xiliens offer a cure for cancer. As Glenn investigates, he develops a romance with Miss Namikawa and uncovers the Xilien's true intentions.
as Astronaut F. Glenn
as Astronaut K. Fuji
as Haruno Fuji
as Miss Namikawa
as Dr. Sakurai
as Tetsuo Teri
as Controller of Planet X
as Chairman of Earth Committee
as Minister of Defense
as Commander from Planet X
as General
as Godzilla
as Rodan
as King Ghidorah
as Astronaut F. Glenn (voice)
as Tetsuo's Mother
as Military Aide
as Namikawa's Associate
as Xian
as Xian
as Councilman
as Female Delegate
as Buddhist Priest
as Councilman
as Official
as Scientist
as Scientist
as Reporter
as News Reader
as Xian
as Xian
as Xian
as Xian
as Xian
as Reporter
as Xian
