Lone Wolf and Cub: Sword of Vengeance (1972)

In this first film of the Lone Wolf and Cub series, adapted from the manga by Kazuo Koike, we are told the story of the Lone Wolf and Cub's origin. Ogami Itto, the official Shogunate executioner, has been framed for disloyalty to the Shogunate by the Yagyu clan, against whom he now is waging a one-man war, along with his infant son, Daigoro.