Like the first two Movie War films, Movie War Ultimatum is split into three parts. The first part is the Kamen Rider Fourze's place five years after the events of the series. Gentaro is now a teacher at Amanogawa High as well as the Space Kamen Rider Club's new academic advisor. The rest of the original Kamen Rider Club members went their separate ways: Yuki becoming an astronaut, Kengo becoming a graduate student at Kyoto Space University to research Cosmic Energy like his father, Miu becoming a model, Shun becoming a professional football player, JK working for a magazine, Tomoko as a novelist, and Ryusei becoming an Interpol agent with Inga Blink. However, a new school club called the Monster League, comprised by a group of psychic children led by Saburo Kazeta who becomes a mutant known as Sanagiman, threatens the school. The Monster League, in turn, is supported by a mysterious man named Kageto Banba who possesses a Zodiarts Switch.
The second part is Kamen Rider Wizard's portion, where Haruto enters the Underworld of an unknown Gate to investigate the mysterious occurrings of monster appearances. He then runs into a young woman named Yu Kamimura who can become Belle Mask Poitrine and can use magic like him.
The third and final part of the film is Movie War Ultimatum. The three Akumaizer from the Underworld to plan to invade the land of the living by using a Monster Army. Kamen Riders Wizard and Fourze, along with the help of Kamen Riders Meteor, Nadeshiko, OOO, Birth, Double, and Accel, must fight to stop the Akumaizer and their Monster Army.
