Sougo is attacked by a Kamen Rider from the future, Geiz Myokoin, but is saved by a girl from the same future Tsukuyomi, who wishes to help him out. With no clear idea of what is going on, his confusions are further pushed with frequent visits from the mysterious prophet named Woz. Meanwhile Another Build is wreaking havoc, and Sougo discovers that the key to defeating this "Kamen Rider Build" is to meet Sento Kiryu.