Invasion of Astro-Monster, known in Japan as Kaijū Daisensō (怪獣大戦争, lit. "Great Monster War"), is a Japanese American science fiction kaiju film directed by Ishirō Honda and featuring special effects by Eiji Tsuburaya. It is the sixth film in the Godzilla film series. The film was co-produced between the Japanese company Toho, and Henry G. Saperstein's American company UPA, marking the first time a Godzilla film was co-produced with an American studio. The cast included American actor Nick Adams and Japanese actors Akira Takarada, Kumi Mizuno and Akira Kubo. The film is the first in the franchise to feature alien invaders, combining the series with outer space themes such as civilizations on other planets and interplanetary space travel.