Novelist and bookstore owner Touma Kamiyama suffers a recurring dream about a place called Wonder World invading the real world and his inability to save a mysterious young girl 15 years prior. His dreams become reality when he is dragged into a war to decide the fate of both worlds, so he takes matters into his own hands when he obtains the means to transform into Kamen Rider Saber.

Touma meets two other members of the Sword of Logos. One is Kento Fukamiya, his childhood friend, and the other is Ryo Ogami, a great swordsman who divides his time between fighting and raising his son, Sora.