Two young boys sneak aboard a spaceship and find themselves whisked away to the mysterious planet Terra. There, they encounter Gamera's old foe Gyaos and two female aliens with a taste for human brains. Gamera must save the children and battle the new monster Guiron, whose entire body is a deadly living weapon.

Cast: Nobuhiro Kajima, Christopher Murphy, Miyuki Akiyama, Eiji Funakoshi, Kon Omura, Yūko Hamada