Shouichi encounters a teenage girl called Sayaka, who ran away from a military facility because of an attack by the Ant Lords. Sayaka has a supernatural ability to foresee the future. Risa Fukami, of the military group GA, wants to use that power to enhance the newly-made G4 System, which was based upon designs stolen from Ozawa. Now, Agito and Gills must fight to stop the Ant Lords' attack, as G3 and G4 settle their score.

Shouichi encounters his old friend and caretaker Dr. Higashi Kunieda. Dr. Kunieda, a friend of Yoshihiko Misugi, took care of him while he was hospitalized with amnesia. After catching up on a year of separation Shouichi abruptly leaves to house to fight an Unknown as Agito Burning Form. Unfortunately, after the Unknown flees Shouichi loses control of himself and attacks Dr. Kunieda, who followed Shoucihi and watched him transform. Dr. Kunieda managed to calm him down but Shouichi becomes to afraid of himself and runs away.

Kamen Riders Agito, G3 and Gills help Televi-Kun against Lords.

This movie is an alternate ending to the series, taking place after the events of episode 46. With only six Riders remaining in the Rider War, Shirō Kanzaki feels that time is running short.

JSDF pilot Akane has a fateful encounter when a new Godzilla emerges in Tateyama. As a countermeasure, a cyborg named Kiryu is constructed from the remains of the original. The machine is discovered to harbor the restless soul of the original monster as Akane must learn to find value in her own life as well.

Mothra and her fairies return to Japan to warn mankind that they must return Kiryu to the sea, for the dead must not be disturbed. However Godzilla has survived to menace Japan leaving Kiryu as the nation's only defense.