Leopard lives with her mother and guardians, Dorothy, Voltkatze, and Elephantus, just outside the rich Yatter Kingdom, several generations after the original Yatterman series. She leads a pleasant albeit destitute existence, unknowing of her ancestors' connections to the famed Doronbow Gang, until she uncovers a painting of Doronjo, Boyacky, and Tonzura in a locked room of her house. Dorothy, Voltkatze, and Elephantus are discovered to be descended from the bad gangsters, which is why they are not permitted to enter the hero Yatterman's Kingdom!