Season 4 serves as a quest for Joker to find the ancient treasure. However, Devil Fang continues to target him and his gang with new hunters and Phantom Thieves after them. Dr. Neo have planned against Phoenix and Hosshi for his own goals.

Season 3 serves as Joker's quest to find an ancient treasure. He was joined by an alien cat named Hosshi and encounters a mysterious phantom thief, Akai Tsubasa. At the same time, he have to combat a mysterious evil organization, the 'Devil's Fang' and against the assassins they sent.

Season 2 serves as a continuation of Joker's journey. At the same time, he has to confront against Professor Clover, Silver Heart's long time archenemy and Shadow Joker, Joker's rival who shares a secret past with him........

Season 1 starts the series introducing the main casts: Joker, Queen, Spade, Hachi, Dark Eye, Roko and Silver Heart. Against them are the police feacturing Inspector Oniyama and his subordinates, Ginko Kurosaki and Momo Shirai and other recurring characters who challenge Joker such as Mr. Kaneari and his secretary, Kaneko. But the main antagonists, Shadow Joker and Professor Clover along with Lady Doubt tend to do more that get in Joker's way.