Kamen Rider × Kamen Rider Wizard & Fourze: Movie War Ultimatum (仮面ライダー×仮面ライダー ウィザード&フォーゼ MOVIE大戦アルティメイタム, Kamen Raidā × Kamen Raidā Wizādo ando Fōze Mūbī Taisen Arutimeitamu) is a Japanese superhero crossover film between Kamen Rider Fourze and Kamen Rider Wizard, while featuring a supporting role from OOO, and serves as the 4th installment of the Movie War series of films. The film features special appearances of characters from several of Shotaro Ishinomori‘s other works while Kamen Rider Beast makes an early-bird appearance in the film ahead of his in-series debut. In the film, the former members of the Kamen Rider Club attempt to move on with their lives when a group of super-powered children known as the Monster Alliance appear and threaten their well-being, while Haruto joins forces with another magical superhero to investigate an incident within the Underworld.
The catchphrase for this film is “The opening of the ultimate showtime! Wizard, a promise for the future. Fourze, a promise for five years ago. In order to fulfill this ‘promise’, they head to the battlefield.” (究極のショータイム、開幕！ウィザード、未来への約束。フォーゼ、5年前の約束。その「約束」を果たすため、いざ決戦の地へ―。, Kyūkyoku no shōtaimu, kaimaku! Wizādo, mirai e no yakusoku. Fōze, 5-nen mae no yakusoku. Sono ‘yakusoku’ o hatasu tame, iza kessen no ji e ―.)