Izo is an assassin in the service of a Tosa lord and Imperial supporter. After killing dozens of the Shogun's men, Izo is captured and crucified. Instead of being extinguished, his rage propels him through the space-time continuum to present-day Tokyo. Here Izo transforms himself into a new, improved killing machine.
A barkeeper saves a Yakuza boss' life and thus makes his way up in the organization. However, his fear of nothing soon causes problems.
After being brutally murdered in a gangster-style execution, Kensuke Hagane finds himself brought back to life by a mad scientist and rebuilt as a robot-human hybrid with a serious thirst for vengeance and the tools to carry it out.
