The Sengoku Rider War (戦国ライダー大戦 Sengoku Raidā Taisen) is a war between the and their armies. The war takes place in an apocalyptic future where the Helheim Forest has taken over the world. This presumably predestined war begins with Gaim and Baron's factions preparing to battle, while Zangetsu's faction observes. As Ryugen kneels beside Zangetsu, it can be assumed that he serves as his vassal. A mysterious woman in a white dress awakens and accidentally drops her flower hair decoration as Gaim and Baron's factions charge at each other. Transform! The Orange from the Sky!?