A young Kamen Rider fan is granted his wish of seeing Riders in person, initiating the ultimate Japanese superhero crossover meta film. The third and final installment of the Heisei Generations series finds Kamen Rider Zi-O and Kamen Rider Build joining forces with all of the other Heisei Generation Riders to reverse the damages of an evil Time Jacker named Tid, and save their legacy. Are Kamen Riders real? Will you believe?

As a computer virus based on Pac-Man invades Japan, a group of doctors attack Genm Corp and begin a wave of terror using stolen Proto Gashats. Ghost and Ex-Aid find themselves at the center of the fight in an effort to protect those most important to them. But they aren’t alone, as Heisei Riders from the past join them to stop Dr. Pac-Man!

Kamen Riders Build and Ex-Aid team up with the legendary heroes of the Heisei Generation - OOO, Fourze, Gaim, and Ghost.