Shinobu, a blind boy, leads a tranquil existence supported by his benevolent instructor and his girlfriend, Mikoto, while practicing daily to master the ancient self-defense martial art called "Mibuchi Toshujutsu." That peace is shattered when a mysterious visitor arrives at the dojo and strips him of everything. This stranger defeats both Shinobu and his teacher, then kidnaps Mikoto. Three years later, determined to reclaim his girlfriend, Shinobu rises from the depths of despair and arrives at an isolated island prison housing only the most heinous criminals. There, a battle royal commences—a free-for-all fight to the death among the villainous inmates!!