Joker is a phantom thief who calls himself the "Miracle Maker", and there is nothing he cannot steal. He goes after one treasure after another, relying on flashy tricks that sit somewhere between science and magic. A dogged police detective, Dokusaburou Oniyama, often corners him, but Joker keeps slipping away. While trying to take the Dragon Gem from the mansion of an arrogant, very rich man, he runs into Hachi, a bumbling yet sincere ninja who wants the same prize and worships him. Joker finds Hachi a nuisance, but after they pull off the job together he grudgingly takes Hachi on as his apprentice. The pair then set out after new prizes and clash with other phantom thieves, some familiar and some new, as Joker competes to be the finest magician of the night in this mystery caper series.