Japanese Civil War

The War (戦争) is a conflict that broke out in Japan of the World of Build ten years following the Sky Wall Disaster which split the once united island into three seperate nations. Though ostensibly a three-way war between the nations of Touto, Hokuto and Seito, it was more accurately a conflict between the pacifist Touto, supported by Kamen Rider Build and his allies, and the warmongering Namba Heavy Industries Ltd. and their benefactor Blood Stalk, whom manipulated the nations of Hokuto and Seito into invading Touto while conspiring with their Deputy Prime Minister Gentoku Himuro to undermine his father, all in order to seize the Pandora Box and gather the 60 Fullbottles needed to open it.

The first phase of the war began when Hokuto, supported by Blood Stalk, launched an invasion of Touto following the supposed elimination of the terrorist organization Faust, which was secretly managed by Gentoku Himuro. Gentoku became Prime Minister in light of his father's ill health, only to be banished from the nation once his father was healed by Misora Isurugi, with the younger Himuro's true nature being exposed. Ultimately, the conflict between Touto and Hokuto was decided by a Proxy Battle in which Seito emerged victorious.

The war continued, however, as Seito, having initially remained neutral while being secretly backed by Juzaburo Namba himself, quickly seized control of Hokuto, whom had been sold out by Stalk, before launching their own invasion of Touto. Ultimately, Seito was represented by Gentoku Himuro as Kamen Rider Rogue in the deciding match of the 3-on-3 Proxy Battle against Touto, who were supported by Hokuto's Kamen Rider Grease. When Touto prevailed against Seito, Prime Minister Masakuni Mido, though devastated, intended to honor his promise to relinquish his claim on Hokuto, the Fullbottles, and the Pandora Box, only to be murdered by Blood Stalk, who applied his appearance to Namba, allowing the CEO to secretly take control of Seito personally and pour the full might of his corporation into an invasion of Touto.