Lupin is caught in a flash of blinding light and finds himself in Showa era Japan circa 1930. He finds that he is the thief "Golden Mask" being pursued by Inspector Namikoshi who looks like Zenigata. "Golden Mask" sets his sights on a national treasure from the Imperial Museum but he must contend with private detective extraordinaire, Kogoro Akechi and the "Black Lizard", who resembles Fujiko. "Black Lizard" has been hired by Colonel Daidoji, assisted by a Major who resembles Jigen and is armed with a Model 14 Nambu Pistol...