The feud between two rival delivery companies, Kibamasa and Okiyama, heats up as the head of Kibamasa falls ill.
Nabeshima Naoshige murders his lord, Ryuzoji Takafusa, seeking to gain power and steal his Lord’s wife. To avoid her fate, Lady Takafusa drowns herself along with her cat in a nearby marsh. A decade later, Naoshige’s efforts to steal another woman trigger a curse on him when she also commits suicide at the same marsh — forcing him to suffer the consequences of his past actions.
In the fourth installment, Musashi's potentially greatest opponent Kojiro jumps in and out of the story at the oddest and most coincidental moments. As his great love Otsu has succumbed to madness. Musashi then sets off to beat the functionaries of a treacherous clan in an arranged duel. 73 against one. Boastful Kojiro watches, secure in the knowledge that only he is a worthy opponent.
