In Italy in the 1930s, sky pirates in biplanes terrorize wealthy cruise ships as they sail the Adriatic Sea. The only pilot brave enough to stop the scourge is the mysterious Porco Rosso, a former World War I flying ace who was somehow turned into a pig during the war. As he prepares to battle the pirate crew's American ace, Porco Rosso enlists the help of spunky girl mechanic Fio Piccolo and his longtime friend Madame Gina.
In the film, the Crisis Empire devise a plan to defeat Kohtaro Minami by reverting him back to his old form of Kamen Rider Black and sending out several revived monsters after him. However, Kamen Rider Black is assisted by another RX, who used a time warp to help his past self. The two are joined by RX's alternate forms of Robo Rider and Bio Rider and the four Kamen Riders combine their powers to defeat the revived monsters.
Prince Bulldont abducts several children and forces them to act in his deadly realistic film, leaving Ohranger to save the day.
