Arsene Lupin III discovers that the spoils from his latest casino robbery are actually "Gothic Bills," legendary counterfeits that are nigh impossible to distinguish from genuine bills. Together with colleague Daisuke Jigen, he heads to the small nation of Cagliostro to investigate the origin of these counterfeits. Upon arrival, they save a girl from a high-speed chase who turns out to be Clarisse d' Cagliostro, the daughter of the late Duke d' Cagliostro. She is running from a sinister plot by Count Cagliostro to steal her family's treasure through a forced marriage. Natural flirt Lupin dislikes seeing a girl in distress and seeks to remedy the situation. Goemon Ishikawa XIII, Fujiko Mine, and Kouichi Zenigata also join the fray, each with their own motivations. As everyone converges at Cagliostro Castle, Lupin reminisces about his visit there 10 years ago, and the castle's secrets emerge from the depths. Lupin and Jigen have just pulled off another million-dollar heist - only to find out that all one million dollars of it are counterfeit money from Cagliostro! Cagliostro has supplied the world with counterfeit money of all nationalities for decades, only surviving because of the global economy's strong dependence on the faux dough.Shortly after crossing Cagliostro's borders, Lupin encounters the lovely princess of Cagliostro, hotly pursued by the Duke of Cagliostro's cronies - and loses her to the Duke's men who imprison her in his heavily-fortified castle. A bit of inquiry reveals that the Duke has plans to marry the princess against her wishes... and perhaps other plans as well, one involving finding a priceless treasure lost for centuries.A beautiful damsel in distress, an evil Count to be smote, a lost treasure, and the biggest counterfeiting racket on the face of the earth... this is an order just too big for Lupin to resist! But it will take the combined effort of Lupin and all of his friends - Jigen, Goemon, Fujiko, the courageous and selfless Princess herself, and even the relentless Inspector Zenigata - to thwart the Duke's plans and save the day! Excitement and mayhem are in store!