The movie begins with Phantoms Medusa and Phoenix approaching some Gates who are trapped in a strange machine and Xatan, Eel and Gahra, a trio of monsters known as the Akumaizers appear before them, claiming that the machine makes use of the captives’ mana to summon revived monsters endlessly as part of their plan to get revenge on the Human Race for banishing them to the underground thousands of years ago. Upon learning that the Phantoms were sent there by their leader Wiseman to assist them, Eel opens a time portal to travel to five years in the future.
Kamen Rider Fourze
Five years later, Ryusei Sakuta, now an Interpol agent, defeats a group of criminals with psychic powers in South America, assisted by Inga Blink, after learning that they work under Kageto Banba, a man with a Zodiarts Switch. Meanwhile, in Japan, the Kamen Rider Club at Amanogawa High School is reduced to one member, a student called Miyoko Ohki whose advisor is Gentaro Kisaragi, who now works there as a teacher. Yuki Jojima is now an astronaut and is about to return from the International Space Station, but another of Gentaro’s students, Saburo Kazeta, causes a ruckus with his psychic powers and runs away with three of his classmates. Gentaro runs after Saburo while fellow teacher Haruka Utsugi tries to contain the other three. However, Saburo transforms into the monster Sanagiman and overpowers Kamen Rider Fourze when Banba appears to give him a powerful device called “Zeber”. Kamen Rider Fourze is rescued by Kamen Rider Meteor and they contact the rest of the original Kamen Rider Club to help them.Some time later, Banba and Saburo assemble other youngsters with special powers to join their crusade to stop space exploration for the sake of focusing on Earth’s problems. Banba instructs them to channel their energies to fully charge the Zeber while he meets Eel and it is revealed that he is in fact working for the Akumaizers. However, Gentaro and his friends arrive with evidence against Banba and the students are dissuaded by them, except for Saburo and his clique. While Kamen Rider Meteor confronts Banba and Saburo’s friends are subdued by the rest of the team, Saburo claims that it is too late for him as he was shunned by his family because of his powers and had already turned into a monster while Gentaro is unlike him, a Kamen Rider. To win his trust, Gentaro destroys his Fourze Driver and claims that he just like him, who decided to give up being a Kamen Rider, Saburo also has the power to change himself into someone different. Miyoko appears to assist the others, just to be kidnapped by Banba who defeats Kamen Rider Meteor. The reformed Saburo transforms into Inazuman and defeats Banba, but Eel uses the Zeber to destroy Yuki’s return module as she descends back to Earth. However, Yuki is saved in the nick of time by Kamen Rider Nadeshiko. Eel then escapes back to the present and Gentaro travels back in time after him, accompanied by Ryusei and Nadeshiko. Before confronting the enemy, Gentaro meets his past self and borrows his Fourze Driver.
Kamen Rider Wizard
Some monsters who emerged from the Akumaizers’ machine are confronted and defeated by Haruto Soma, accompanied by his friends Koyomi, Shunpei Nara and Rinko Daimon. However, the Akumaizers prove themselves too strong for Kamen Rider Wizard to defeat by himself and they leave to a Gate’s Underworld taking the Zeber with them while instructing Phoenix and Medusa to stop Haruto and the others. However, instead of doing as asked, the Phantoms flee, claiming that they do not want to associate themselves with the Akumaizers. Haruto then dives to the Underworld after them but some monsters appear from the machine and Shunpei and Rinko accidentally enter the portal opened by Haruto, leaving Koyomi alone with the creatures. The three awake in what seem to be their own world, with no memories of what happened, but finds those around her, including some familiar faces, behaving strangely, as they only seem dedicated to arrange the birthday party for a person called “Poitrine”.While exploring the streets, Haruto finds some children attacked by monsters and just while Rinko and Shunpei leads them to safety, Haruto confronts the enemies until a young woman called Yu Kamimura appears and transforms herself into “Belle Mask Poitrine” to defeat them. Some of the enemy monsters flee and Yu claims that they must not be pursued as they had quit the fight. While the children ask Rinko and Shunpei to remember the truth, Yu is brought by Haruto to the Antique Shop Omokagedō to celebrate her birthday with his friends. Haruto then awakens at the start of the same day and remembers the truth. When the monsters appear to attack the children, just like in the previous day, Haruto steps in and instead of waiting for Poitrine, finishes the enemies by himself. Both the passerby and Yu complain with Haruto for stopping the monsters instead of Poitrine and it is revealed that just like them, the four children are trapped in Yu’s Underworld by the Akumaizers’ machine. Haruto tries to dissuade Yu but Gahra appears to stop him and convinces her to have Haruto join the endless loop as well until Haruto and the children bring her to her senses. With Yu free from the Akumaizers’ control, Kamen Rider Wizard and Poitrine join forces against Gahra until the Akumaizers reunite, fending off Kamen Rider Wizard and taking Poitrine away with them after throwing several monsters to deal with Haruto.
Movie War Ultimatum
Left behind in the real world, Koyomi is about to be attacked by the monsters until Kamen Riders Fourze, Meteor, and Nadeshiko appear to protect her. Meanwhile, Wiseman reveals to Phoenix and Medusa that when the Akumaizers throw the fully charged Zeber into the ocean of magic beneath the Underworld, the outside world will be overflown with enough magic energy to kill all humans. Upon learning the situation from Koyomi, Gentaro makes use of a Magic Ring that somehow is in his possession to gain entry in Yu’s Underworld with his companions, arriving in time to save Haruto from the monsters. Gentaro recognizes Haruto, who claims to not know him. However, the Akumaizers send a larger force to deal with the Kamen Riders as they escape with Poitrine and the Zeber. Koyomi is attacked by Ghouls that have emerged from the machine and is saved by Eiji Hino, who uses his powers to reach the children in the Underworld and grant them Magic Rings which they use to summon Kamen Riders OOO, Birth, Double, and Accel.After disposing of the enemies, the eight Kamen Riders rush to intercept the Akumaizers’ vehicle and rescue Poitrine. Eel and Gahra are destroyed, but Xatan makes a last effort to take the Zeber to the ocean of magic and both Fourze and Wizard are powered up by their companions to finish Xatan and destroy the Zeber for good. Back from the Underworld, Gentaro instructs Haruto to return the Fourze Driver to his past self and is sent back to the future with the others. All the Gates are saved, but while the children do not remember what has happened, Yu, who is revealed to be the owner of the Doughnut Shop Hungry does, much to Haruto’s chagrin. Back to his own time, Gentaro learns from Saburo that he and his friends will dedicate themselves to fight those who abuse their psychic powers and the Kamen Rider Club lends him their support, while the past Gentaro is approached by Haruto who returns his Fourze Driver and also gives him the same Magic Ring his future self used previously, claiming that he will eventually need it. After the credits, a gold-colored Kamen Rider makes a brief appearance.Movie Wars Ultimatum is a fun way to kill two hours if you just want to see a crossover between two particularly flashy Kamen Riders.