Tokuzo Tanaka's The Betrayal could almost be a prequel to Kihachi Okamoto's Sword of Doom, in that it shows how a loyal Samurai becomes disillusioned with the traditional honor code and could eventually turn to amorality. Raizo Ichikawa, who I mainly know from the Shinobi no Mono movie series, is the honorable and skilled warrior forced by his clan senior (and father of his fiancee) to take the blame for the back-stabbing murder of a rival clan member in order to save the home clan's face. Ichikawa does so on the promise of the matter being resolved in a few months, only to find that the old man has died in the interim and there is no one that can vouch for his innocence (although I don't know why his fiancee - Kaoru Yachigusa from Hiroshi Inagaki's Samurai trilogy - who is a witness to this conversation, cannot vouch for his innocence, especially after her father is dead).
Ichikawa becomes an outcast, hunted by both the rival clan and his own clan. He disclaims Samurai honor as meaningless, although his conscience still pushes him towards a personal ethical code. He has multiple encounters with the various clan members in which his skills help him to escape. In the end he is surrounded by a literal army of enemies - his own clan, the rival clan and people interested in the bounty for his head. It is a scene of highly exaggerated combat: Ichikawa slays more than a hundred foes coming at him with swords, lances, ladders, ropes, handcarts. Even his enemy is forced to admit that with such skill and valor, he could not have been the backstabber, but for the sake of clan honor he must slay him.
For all the action, The Betrayal is primarily a melodrama, and it does lay it on a bit thick. Like I said, I am not sure why the fiancee character could not clarify matters to her clan (it would be another matter if she did not know). But the film is shot with style (Japanese film expert Tom Mes' selected scene commentary nicely dissects the visual choices Tanaka makes) and subverts some expectations - a thief character who attaches himself to Ichikawa sees his ethical behavior, but does not flinch from betraying him later. The climactic fight is a doozy, although a lot of the time the enemy pretty much fall on to Ichikawa's sword while making the most inept stabs at him (There is no way he could have overcome those odds if they had shown the slightest competence). The film ends on an ambiguous note where we don't know if Ichikawa's character will be left alone or further pursued by his enemies. Who knows, may be he could end up as the amoral character Tatsuya Nakadai played in Sword of Doom.
A few words on the blu-ray from Radiance Films:
Radiance's blu gives a fine presentation of the B&W widescreen feature, with solid grayscale and contrast. The audio is a mixed bag, with significant distortion in the upper registers, especially noticeable during Akira Ikufube's excellent score. Extras include the aforementioned selected scene commentary, a visual essay by Mes where he discusses Tozuki Tanaka's style (I feel he extrapolates a bit too much here about the thematic elements), and a nice comparison by Philip Kemp of The Betrayal to a silent-era movie of which it is said to be a remake. The booklet in the limited edition contains a scholdarly essay by Alain Silver.

