Gamera vs. Zigra

A Japanese moon base is destroyed by a spaceship from Zigra, which seeks to take over Earth's oceans for its own alien species. Gamera must defend humanity as all of Japan rallies behind him. Kenichi Ishikawa and his father Dr. Yosuke Ishikawa are among those captured by the aliens, but with the help of their friend Helen Wallace, they escape from Zigra's spaceship and later join forces with Gamera to stop the alien monster.