Assassination begins with the events of 1853 when "four black ships" anchored at Edo Bay, sparking civil unrest and the major political manoeuvring that saw the end of the Tokugawa Shogunate. At a time when assassination had become a disturbing political tool, Shinoda's film follows Hachiro Kiyokawa, an ambitious, masterless samurai whose allegiances drift dangerously between the Shogunate and the Emperor.
Iemon Tamiya is an impoverished masterless samurai who craves a better life, which he cannot have because of his marriage to Oiwa, who is completely devoted to her husband.
Part 2 starts where the first film ended, with Iemon disposing of the bodies of his wife and Kohei, marrying upward, and being blackmailed by the evil Naosuke.
