Eight years after the battle for the Book of Omniscience, the peaceful lives of Touma, Rintaro, Mei and Kento are troubled by a mysterious new Falchion who can seemingly erase people from existence altogether.

Touma, Yuri and Mei somehow ended up in the World of Zenkaiger while four Zenkaigers, except Juran, ended up in the World of Saber. The reason for their swap is due to a man who wishes to rid the world of heroes. How does a teenage boy manga artist tie into this? And why are they sent into different stories filled with previous Kamen Riders and Super Sentai Teams?