Something is destroying Japanese subs searching for the remains of Mechagodzilla (after the robot's destruction at the hands of Godzilla in Godzilla vs. the Cosmic Monster). Marine biologist Akira Ichinose (Katsuhiko Sasaki) believes that it could be Titanosaurus, an underwater dinosaur that Dr. Shinzo Mafune (Akihiko Hirata) claimed to have discovered. This claim-along with his theories of controlling sea life remotely to aid in aquaculture-resulted in Mafune being laughed out of academia. Ichinose seeks out Mafune, meeting his beautiful daughter Katsura (Tomoko Ai), who claims Mafune is dead and his notes destroyed. What is Mafune and his daughter's connection to Mechagodzilla and the aliens who control them, and will Ichinose be able to figure it out before it's too late?![]()
