[The film] purports to pitch a battle between pragmatism and superstition, but it’s really about the selfishness of individual agency versus the righteousness of the collective spirit. Yoshihiro’s ailment turns out to be merely psychological in nature, thus allowing him to overcome it and assume his socially sanctioned role as an upstanding, selfless citizen... But these intertwining narratives take a backseat to the central message, aimed right at the audience: do your part for the nation.
Individual stories of more genteel matters eventually take hold (one of which, concerning the ownership of an ancient sword, lends the film its title), but to Kinoshita's credit, he doesn't compartmentalize his efforts. The war scenes, while not on par with the eventual innovation of, say, Seven Samurai, are in fact more strategically realized than what even Kurosawa himself was doing concurrently with his first films.
In the aftermath [of The Battle of Mikatagahara], the camera tracks over slain samurai; a dissolve reveals a modern memorial to the battle; a cut shows soldiers training on the same land. The moment almost evokes A Canterbury Tale (1944), in which a transition from past to present reminds us of the cultural values being fought for.