In a earth with an alternate background, an incredible war last but not least comes to an end leaving the earth diseased and polluted. The geneticist Dr. Azuma vies for help from the government for his neo-cell remedy that he claims can rejuvenate the body and regenerate humankind. The federal government leaders, guarding their individual deeply entrenched powers, turn down the professor. Driven to finish his get the job done, Dr. Azuma accepts a secret present from a sinister faction from the potent military. Soon after an incident takes place in Dr. Azuma's lab, a race of mutant people identified because the Shinzo Ningen are unleashed upon the earth. Now only the warrior identified as Casshern, reincarnated with an invincible body, stands amongst the Shinzo Ningen as well as a earth around the brink of annihilation.