Zatōichi tekka-tabi (1967)

Zatoichi comes upon the town of Tonda, overrun by gangsters. Using one of his favorite techniques, Zatoichi proceeds to win 8 ryo in a rigged gambling game. Of course, the local gangsters attempt to kill him, and the adventure begins. It turns out a blacksmith named Senzo examines Zatoichi's cane sword, and discovers it to be forged by his old mentor. Senzo discovers the sword is at the end of its usefulness and will break when it is used next.