Zatoichi (Shintarô Katsu) discovers that his new lord and employer suffers from a mental illness that, if made public, could extinguish the lord's empire and destroy his loyal samurai. But the samurai know something is amiss. Zatoichi holds a secret, too, and they're determined to get it no matter what. In a final duel, Zatoichi must face the infamous one-armed samurai. Kazuo Mori directs this action-filled drama.