The man who hails from the future, Geiz, attacks Sougo! Tsukuyomi, a girl who also hails from the future, came to help out Sougo, but Sougo has absolutely no idea what's going on! A mysterious prophet named Woz is also starting to appear frequently before Sougo. The creature, Another Build also attacks. What could be the key to defeating this "Kamen Rider Build"? Sougo makes his way towards the Nascita Cafe to meet with Kiryu Sento...

A strange collaboration between Geiz and Tsukuyomi happens with Sougo in the year of Build, 2017. They both decide to go to Sougo's school to keep a closer eye on him. While there, they discover a growing popularity of a "game that no one can clear" with the other students. Rumors surrounding the Genius Gamer M start to surface as well, as they decide to chase the mystery by finding him. And Sougo and the others end up meeting...? Suddenly, a new Time Jacker, Ora appears!

Ora has given a father the power of Another Ex-Aid as part of a bargain for his son's life. Geiz and Sougo travel back to 2016 to help him.