is a 1965 Japanese kaiju film directed by Noriaki Yuasa, with special effects by Yonesaburo Tsukiji. Produced and distributed by Daiei Film, it is the first film in the Gamera franchise and the Shōwa era. The film stars Eiji Funakoshi, Harumi Kiritachi, and Junichiro Yamashita. In the film, authorities deal with the attacks of Gamera, a giant prehistoric turtle unleashed in the Arctic by an atomic bomb. The success of The Birds and Toho's Godzilla films influenced studio head Masaichi Nagata to produce a similar film. In 1964, Daiei attempted to produce Nezura, with Yuasa directing. However, the project was shut down by the health department, since the project was to have used dozens of live rats. Nagata then conceived Gamera to replace Nezura on the schedule. Due to a low budget and tight schedule, Yuasa was forced to use outdated equipment, faulty props, and faced belittlement from colleagues. Yuasa was determined to complete the film with Daiei's resources, despite brief talks of hiring Tsuburaya Productions to finish the film. Gamera, the Giant Monster was theatrically released in Japan on November 27, 1965. A localized version with new footage was theatrically released in the United States on December 15, 1966 by Harris Associates, Inc. and World Enterprises Corporation as Gammera the Invincible. This was the only Gamera film in the Shōwa era to be given a theatrical release in the United States. The film was followed by Gamera vs. Barugon, released on April 17, 1966. Plot In the Arctic, an unknown aircraft is shot down by an American jet fighter. The aircraft crashes and its cargo, an atomic bomb, explodes. The explosion awakens a giant prehistoric turtle with tusks. Japanese scientists on an expedition nearby, Dr. Hidaka, his assistant Kyoko and reporter Aoyagi, are given a stone tablet by an Eskimo chief, who explains that the creature is called Gamera. Gamera destroys the expedition ship and escapes. Sightings of flying saucers soon surface in Japan. In Sagami Bay, Toshio (a boy recently forced to release his pet turtle) and his family encounter Gamera, who attacks their lighthouse. However, Gamera saves Toshio from falling to his death. Toshio becomes attached to Gamera after finding his pet turtle gone, believing it turned into Gamera. Upon returning to Japan, Dr. Hidaka, Kyoko, and Aoyagi accompany the military when Gamera approaches a geothermal power plant. Despite attempts to prevent its approach, Gamera proceeds to