Mori Kojiro, a member of the Akō Ronin, fails to identify Kira Kozukenosuke before their attack and is publicly banished by Ōishi Kuranosuke. Ōishi later apologizes privately, revealing that Kira has a decoy and assigning Mori a secret mission to kill the real Kira if necessary. Devastated, Mori finds solace with Okame, a local bar owner. After the ronin avenge their master, Mori, believing their mission complete, plans to leave his samurai life for Okame. However, Terazaka Kichiemon reveals that Kira was not killed but fled, and the decapitated man was a decoy. Mori decides to complete his mission and hunt down the real Kira.
Unfortunately the movie Ronin on a Mission is not yet available on HBO Max.
| Directing | Tokuzō Tanaka | Director |
| Writing | Takuzō Kawatani | Screenplay |
