10 years ago, the “Pandora Box” was found on Mars. On Earth, it created walls that divided Japan into Touto (Eastern Capital), Hokuto (Northern Capital) and Seito (Western Capital) and brought along the Smash, unidentified life forms that attack people. Sento Kiryu, a prodigy physicist, transforms into Kamen Rider Build to fight the Smash.
The Touto government requests his help in deciphering the mystery behind the Pandora Box and the Smash. There
