Ryuga Banjo is the emotional core of Episode 1. He is arrested for the murder of his lover, Kasumi Ogura, a crime he did not commit. When we meet him, he is a coiled spring of anger—wrongfully imprisoned, betrayed by a system he doesn’t understand.
The episode cleverly links his identity crisis to the transformation system. To become Build, he must twist the Rabbit and Tank FullBottles together—two incompatible objects (speed vs. armor) forced to coexist. That is Sento: a gentle musician and a ruthless physicist, a victim and a weapon. Kamen Rider Build Tap 1
This stands in stark contrast to the Smash, which are pure, unthinking chaos. Faust’s goal, revealed via the mysterious Night Rogue, is to create the ultimate chaotic being. Build is the answer to that: controlled chaos. Ryuga Banjo is the emotional core of Episode 1
By rejecting the typical monster-of-the-week formula in favor of a slow-burn conspiracy thriller, Build announces itself as the most literate Kamen Rider season in years. Every fight is a test. Every transformation is an identity crisis. And the greatest mystery is not the Pandora Box—it is the man holding the key. The episode cleverly links his identity crisis to
Following the more light-hearted Kamen Rider Ex-Aid , Episode 1 of Kamen Rider Build (2017) arrives as a cold, calculated reset. Within its first five minutes, the show establishes a tone of paranoia, mystery, and science-fiction body horror. The title, “They Are the Best Match,” operates on three levels: the literal combination of FullBottles (Rabbit & Tank), the forced partnership between Sento Kiryu and Ryuga Banjo, and the volatile fusion of human will with alien technology (Pandora Box). This premiere is a masterclass in efficient world-building, introducing a fractured Japan, an amnesiac genius hero, and a transformation system that feels less like magic and more like a controlled explosion.
Introduction: A Gambatte Reboot
This is a radical departure from typical Kamen Rider protagonists (who are usually energetic high schoolers or righteous cops). Sento is a man running from a past he can’t access, yet his body remembers—his hands instinctively perform complex chemistry, his eyes calculate angles for a Rider Kick. His catchphrase, “Let’s begin the experiment,” is a coping mechanism. Every fight, every transformation, is an attempt to reverse-engineer the mystery of who he is.