One month ago, a strange phenomenon suddenly fused the human world with the parallel world of Kikaitopia. Despite this, the inhabitants of both worlds, humans and Kikainoids, quickly got along and live peacefully together.
In the present, however, their lives are threatened by Kikaitopia's evil rulers, the Tozitend Dynasty, who seek to conquer all parallel worlds. To face this new threat, a brave and energetic young man named Kaito Goshikida inherits the powers of all previous Super Sentai. Transforming into Zenkaizer, he joins forces with the Kikainoids Juran, Gaon, Magine, and Vroon to save the multiverse from Tozitend and find Kaito's missing parents as the Zenkaigers. The conflict later intensifies with the arrival of the World Pirates. Led by Zocks Goldtsuiker, who can transform into Twokaizer, the World Pirates oppose Tozitend in pursuit of their own objectives and occasionally ally with the Zenkaigers for the sake of it.