A wandering ronin by the name of Hirano Sugata comes across a group of young, rash and well meaning samurai that are caught in between a clan dispute. Willing to help the samurai, despite his limited sword expertise, the ronin begins to trick the opposing forces into disposing of each other.

This was Akira Kurosawa's first attempt at adapting Yamamoto Shugoro's novel "Peaceful Days" to the big screen. The adaptation was planned to be faithful to the original source in many ways, but reportedly the role of the ronin, of which there were two in the novel, had been changed to one character. Although Kurosawa wrote the script, this production was intended to be helmed by Horikawa Hiromichi, Kurosawa's assistant director on movies like Throne of Blood (1957). Several actors were attached to the concept, including Frankie Sakai and Keiju Kobayashi.

The project was not meant to be, though, as Toho halted production while Kurosawa went on to make Yojimbo in 1961. When that film became a mammoth success, though, Toho requested that Kurosawa produce a sequel, which promoted the director to revisit his canceled script for Peaceful Days. Kurosawa began to modify the concept, completely removing the "weak" ronin in favor of Toshiro Mifune's character from Yojimbo (1961): Sanjuro. This was a radical change to the production, as a once inadequate fighter, who was forced to rely on his wits, was being replaced by someone who could kill an entire group in a matter of seconds. Thankfully, Kurosawa did not take the easy way out. Rather then haphazardly placing Sanjuro in the story, Kurosawa reworked it further, changing the scenarios to fit the character's skills while also infusing the screenplay with more elements of humor. The antagonist was also changed to a corrupt government body, separating the storyline further from the previous film. Dubbed Sanjuro, the ending result was released in 1962. This wouldn't mark the end of adapting Yamamoto Shugoro's novel to the big screen, though, as Kihachi Okamoto would give his own go at the "Peaceful Days" story, which he released in 1968 under the name Kill!.

It should be noted that the exact date of release for Peaceful Days is unknown at this time, although it's clear that by 1961 Toho was no longer pursuing the development of the project.