Ryo Narushima is a student who has served prison time for killing his parents. Once he is released, he trains to become a professional kick-boxer.

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.

Two contract killers cross paths in the middle of the same job and realize they are childhood friends. Together they take a break from killing and visit the small island they once called home. After reflecting on their past lives they decided to team up and use their talents in killing for good... much to the upset of the crime syndicates.