Once upon a time, in feudal Japan, a seemingly endless war had broken out. And now, the demon shogun Kigai has kidnapped Princess Koto as a sacrifice for his resurrection. But two ninja (named Guren and Gunjo) have arrived as humanity's last hope. Together they travel the demon-infested country to find Kigai, stop him from sacrificing Princess Koto, and save her at all costs. And thus a new war had spawned, humanity versus the demon race.