A huge army of enemies from the future world suddenly attacks through a time-space gate! Houtaro Ichinose/Kamen Rider Gotchard and the others manage to fight back. In the future, there resides Houtaro 20 years later, Kamen Rider Gotchard Daybreak, who saved Houtaro and his friends from their predicament many times in the past. "I have to save him this time!" Catching wind of the crisis in the future, Houtaro and his friends set off on the Gigantliner on a great adventure across time and space to the future where Daybreak resides!