Kamen Rider Build the Movie: Be the One (劇場版 仮面ライダービルド Be The One, Gekijōban Kamen Raidā Birudo Bī Za Wan) is a 2018 Japanese superhero film, serving as the film adaptation of the 2017-2018 television series Kamen Rider Build, taking place between Episodes 45 and 46 of the TV series and featuring the debut of Kamen Rider Zi-O's titular protagonist.