By chance, Shoma meets a tough-looking man named Sujimoto and decides to help him with his work as he is asked.

Then Sujimoto is attacked by a Granute. Shoma receives a call from the Gochizo and rushes to the scene, where he transforms into Gavv and challenges the Granute to a fight.

The Kamen Rider appears! Hanto receives the news from Sachika and witnesses Gavv's battle...!?