Mirai Ninja: Keigumo Kinin Gaiden (未来忍者：慶雲機忍外伝, lit. "Future Ninja: Stealth Joy Cloud Device Side Story"), known as Cyber Ninja in the United States, Warlord in Canada and Robo Ninja in the UK, is a 1988 Japanese science fiction action film directed by Keita Amemiya, which was co-produced and released by Namco that premiered on October 1988 at the Tokyo International Fantastic Film Festival. Two months later, it was released as a direct-to-video film on December 2, 1988. The film is based on the arcade game of the same name which was also developed and released by Namco.