Kamen Rider Reiwa: The First Generation
is a 2019 Japanese superhero film in the Movie War line of the Kamen Rider Series. It serves as a crossover between the television series Kamen Rider Zero-One and Kamen Rider Zi-O and is the fourth film of the Generations series. The film also pays a tribute to Kamen Rider Zero-One, the original Kamen Rider series and the entire Heisei Kamen Rider Series as a whole. It also introduces Gai Amatsu as Kamen Rider Thouser.
The Hiden Zero-One Driver can only be used by the company's president. Whose will was the one that led to the creation of this device and it falling in the hands of Aruto Hiden? Zero-One's birth story will be revealed!