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.
Nick Adams
Astronaut F. Glenn
Akira Takarada
Astronaut K. Fuji
Keiko Sawai
Haruno Fuji
Kumi Mizuno
Miss Namikawa
Jun Tazaki
Dr. Sakurai
Akira Kubo
Tetsuo Teri
Yoshio Tsuchiya
Controller of Planet X
Takamaru Sasaki
Chairman of Earth Committee
