Seito challenges Touto to a best-of-three battle to decide who keeps Pandora's Box; Sento works to find a counter to Black Hazard's berserk state.

Ryuuga is tricked into losing his match; Build and Rogue face off as Sawa arrives with the schematics stolen from Sento.

Kamen Rider Rogue receives the data on Build's Rabbit Rabbit form, forcing Sento to unleash Tank Tank form; Sawa's backstory is revealed while Kazumi rescues civilians; Nanba decides to not play fair, taking control of Seito and declaring war.