The immortal vampire gang led by Princess --Kikiou, Ryuuki, and Shuuran -- is slowly but inexorably taking over Demon City Shinjuku. Its citizens and the administration alike are turning into vampires. Mephisto has apparently allied himself with them of his own accord. Setsura Aki stands alone on the brink of extinction, tested by one desperate counterattack after the next. Intending to snuff out his life once and for all, Princess unleashes the self-regenerating Kazikli Bey (better known abroad as Vlad the Impaler, the original Dracula). Meanwhile, concerned about the worsening state of affairs in Shinjuku, a team of foreign legionnaires -- Special Forces Operational Detachment "F" -- is dispatched to Demon City.