Prologue

Humanity is at war.

A war against a group of unknown ship-like beings called Sirens. To combat them, humanity made the shipgirls, female spirits of warships born from Wisdom Cubes. As of now, the war is now at a stalemate and it seems like the different ideas of the major fractions may doom mankind.

However, from the chaos of the three-way war, a new warrior is born in a new era. He is the vanguard of the Reiwa era and the world's first Kamen Rider.

Kamen Rider Zero-One!

"There's only one person who can end this war, and that's me!"