Though Kinji Fukasaku is best known for making Battle Royale and a series of 70s/80s Yakuza films, he's actually pretty competent at directing samurai films with a darker edge. Sadly, he didn't produce too many in his career, so Crest of Betrayal is a film that needs to be treasured and cherished.
The plot focuses on Tamiya Iyemon, one of the 47 ronin who wandered the land when their master died. He falls in love with Oiwa, a prostitute who earns an extra buck working in local bathhouses. It's all pretty basic samurai stuff, though the second half of the film does have a darker/more fantastical edge to it.
The first half is a little dull. A bit too much time is spent on the setup, but once all the pawns are in place and the darker and weirder second half kicks off, it's clear that Fukasaku really feels at home in this genre. Some stark, colorful imagery, decent performances and a solid ending make this another noteworthy Fukasaku flick.