The fate of the world lies in the hands of one mechanical boy. Can he grow up fast enough to save us?

Ultimo and Vice are Karakuri Doji, the mechanical embodiment of pure good and pure evil, devoid of human emotions that can cloud one's judgment. Their purpose: to battle to the death to prove once and for all whether good or evil is the most powerful force in the universe.

Yamato's best friemd Rune is now a doji master to the envious trickster Jealousy. But why is Rune using Jealousy to attack Yamato and Ultimo? The answer lies deep in the past and will shock everyone... even Rune! Plus, meet Murayama, a warrior with prophecy that could spell some serious trouble for the entire world.