In this thrilling episode following the events of Urotsukidoji III, the survivors of the Azuma kingdom genocide embark on a dangerous journey aboard a futuristic tank. Their destination: Osaka, where they must confront the formidable Overfiend and their own destinies. Along the way, they stumble upon a mind-boggling civilization ruled by cruel children over the adults. Amano Jyaku becomes their only hope to rescue his friends from this sinister land and its malevolent ruler, Ellis. Just when tensions rise, Sui Kaka Ju’s sister Yoenhime summons the powerful Munhihausen and transforms into the formidable Yoenki, seeking revenge against Amano for her brother’s death. But Munhihausen harbors his own hidden agendas. Brace yourself for the ultimate climax in Osaka, as Kiojo, the innocent Himi, and the Chojin come face to face.