Terror of Mechagodzilla

Terror of Mechagodzilla released in Japan as Mekagojira no Gyakush ? , lit. Counterattack of Mechagodzilla is a 1975 Japanese science fiction kaiju film produced by Toho. Directed by Ishir Honda and featuring special effects by Teruyoshi Nakano, the film starred Tomoko Ai, Gor Mutsumi, and Akihiko Hirata. This film was the fifteenth and final film in the original and Showa series of Godzilla films, before the series reboot in 1984. A direct sequel to the previous years Godzilla vs. Mechagodzilla, this film was the least successful commercially of the entire Godzilla franchise. The movie takes place between Godzilla vs. Mechagodzilla and Destroy All Monsters. This was the last film directed by Honda.

Continuing after the end of the previous film, Interpol agents, led by Inspector Kusaka, search for the wreck of Mechagodzilla at the bottom of the Okinawan Sea. Using the submarine, Akatsuki, they hope to gather information on the robots builders, the alien simians. The Akatsuki is suddenly attacked by a giant aquatic dinosaur called Titanosaurus, and the crew vanishes.Interpol starts an investigation into the incident. With the help of marine biologist Akira Ichinose, they trace the Titanosaurus to a reclusive, mad scientist named Shinz Mafune, who wants to destroy all mankind. While Ichinose is visiting his old home in the seaside forest of Manazuru, they meet Mafunes lone daughter, Katsura. She tells them that not only is her father dead, but she burned all of the notes about the giant dinosaur at her fathers request. Unknownst to them, Mafune is still alive and well. He is visited by his friend Tsuda, who is an aide to the simian alien leader Mugal. He is leading the project to quickly rebuild Mechagodzilla. Mugal offers their services to Mafune, so that his Titanosaurus and their Mechagodzillawill be the ultimate weapons. They hope to wipe out mankind and rebuild the world for themselves. ........

Source: Wikipedia