The film follows the story of Sugi Toranosuke, a ronin, who returns to his home town of Edo many years after his attempted suicide as a sickly child. Rescued and adopted by a master swordsman, he has grown into a master swordsman and a very kind gentleman. The time is around 1868 the year that the nails were finally put into the coffin containing the feudal system that nurtured and sustained the samurai. Sugi is confused and unsure about what is happening but his teacher wants him out of the chaos of the multiple power struggles between the various clans.
In Part I we see the young would-be swordsman setting out to achieve greatness in war, achieving nothing because fighting on the losing side, & then beginning his long period of wandering & training, with the goal always in mind of his duel with Kojiro. Part II builds toward that great duel on Ganryu Island, with considerable focus on Musashi's planning & forethought as to how to gain an advantage.
Kingoro Tamai moves with his wife and son to the port city of Wakamatsu. He organizes the Tamai-gumi, a stevedore group, to vie for work with two other powerful groups. Gingo is Tamai's chief rival who falls in love with the latter's wife and tries to kill Tamai.
It was five years ago when Minako spent a night with Sozo, younger brother of her ex-husband. She now lives in a local town with a rich old man who owns a dry goods store. Minako travels to Tokyo on business every three months, during which time she continues to meet Sozo, who has married the daughter of his respected teacher.
