Juzaburo Namba

Juzaburo Namba is the CEO of Namba Heavy Industries and one of the five main antagonists of Kamen Rider Build alongside Night Rogue, Blood Stalk, Yoshiko Tajimi and Masakuni Mido. He is a wealthy businessman and the one behind Faust, having funded the organization's human experiments and operated it as a covert research wing of his company. He seeks to start a war between the three divided regions of Japan as part of a plan to seize the Pandora's Box for his own ends.

As the Japanese Civil War breaks out, Namba aligns himself with Seito and supplies them with his company's more advanced products to given them an advantage over the other regions. He later assassinates and assumes the identity of Seito's Prime Minister, Masakuni Mido, after Mido refuses to follow his suggestions. Initially seeking only to profit from the Japanese Civil War, Namba eventually begins seeking to use the energy of Pandora's Box to unify all of Japan under one state controlled by him and eventually the world.

Namba serves as a background antagonist in the "Birth" arc, the main antagonist of the "War" arc and a major antagonist in the "Evolt" arc.

He was portrayed by Akira Hamada, who previously played Mr. Titan in Kamen Rider Stronger.