The abrupt ending of the film is due to the fact that it was originally intended to be the first part in a trilogy of films based on a lengthy Japanese novel. Nakazato Kaizan's 41 volume historical novel focused on the Edo period in Japanese history when the shogunate collapsed and a new government arose that revolved around the Emperor. It was the longest novel in Japan - encompassing 1533 chapters and over 5 and a half million Japanese characters - until the publication of Sohachi Yamaoka's serialized novel "Tokugawa Ieyasu", which is reportedly the longest novel in any language.
Jim Jarmusch has said the film helped him to stop smoking and watched it every day until he did.
The distinct straw hat worn by the character Ryunosuke Tsukue (portrayed by Tatsuya Nakadai) is a traditional Japanese straw hat often associated with ronin. The style of hat is known as roningasa. 'Ronin' meaning masterless and wandering samurai, and 'gasa' meaning hat."
During one scene Nakadai's character is stabbing the mats at his feet. This combined with the fact that real swords were used during filming, led cinematographer Hiroshi Murai to repeatedly remind Nakadai to not cut off his own big toe while filming.
This is the sixth film to feature both Tatsuya Nakadai and Toshirô Mifune, and it is the second of which not to be directed by Akira Kurosawa.