Kihachi Okamoto's 1966 film The Sword of Doom (in Japanese, Dai-bosatsu tôge) is perhaps one of the darkest films in the chanbara genre. Okamoto, who also directed 1968's dark comedy Kill!, was deeply affected by World War II, and that led to his films often having darker edges to them. Even the setting for The Sword of Doom is bleak, as it takes place during the last days of the Tokugawa shogunate (or even the shogunate in general).

The film centers around the samurai Ryunosuke Tsukue (played by Tatsuya Nakadai), who is easily one of the greatest antiheroes ever created. The film opens with a young woman and her grandfather, who are pilgrims, climbing a mountain and finally reaching the top. On the top, there is a small Buddhist shrine, so while the woman is off getting water for them, he is praying at the shrine. He prays to Buddha for death, as he believes his granddaughter is unhappy as a pilgrim. Lo and behold, Ryunosuke shows up, and asks the man if he is a pilgrim. When the man gives his answer, Ryunosuke brutally kills him with one cut from his blade. The old man has a bell on him, and it rings, unsettling both Ryunosuke and the audience. Ryunosuke then continues on, leaving the young woman to find her dead grandfather a few minutes later.

The film primarily asks the question if humans are inherently evil. Toshirô Mifune, who plays a small but pivotal role in the film, claims that, "The sword is the soul. Study the soul to know the sword. Evil mind, evil sword." However, the opposing viewpoint is that Ryunosuke has been "corrupted" by the sword, because the sword has given him the ability to easily kill. The film doesn't give any easy answers, and leaves it up to the viewer to decide.

As the film progresses, we don't know exactly what Ryunosuke is. He's an antihero for sure, but that's about it. He shows little emotion during the film (he only laughs perhaps two or three times, and each time is really eerie), and technically he only kills when he is forced to or when the victim actually requests death. Is Ryunosuke evil? Perhaps he truly is doing good, and acts as some sort of Angel of Death? Or perhaps he is simply driven insane by his deeds? Once again, the film doesn't give us any answers and leaves it up to us to decide.

The biggest complaint people seem to have with the film is the ending, or lack thereof. You see, the film ends on a freeze frame, and doesn't give you any sort of concrete ending. A big part of this is because the film is based on an uncompleted novel by Kaizan Nakazato of the same name - Dai-bosatsu tôge, which literally translates to Daibosatsu Pass. Now, I'm not sure of the novel's ending (or should I say, what ended up being the ending), but the film ends wonderfully in my opinion. The film's ending gives the feeling that, even when faced with certain extermination, evil will always find a way to escape.

Overall, this film comes highly recommended. The cinematography is once again wonderful, and additional props to the choreography in the fight scenes. However, this film is quite dark, so don't expect light viewing (but then again, the vast majority of the best films aren't).