Haiyu-za Film Production Company Ltd.

Legendary swordplay filmmaker Hideo Gosha's Sword of the Beast chronicles the flight of the low-level swordsman Gennosuke, who kills one of his ministers as part of a reform plot. His former comrades then turn on him, and this betrayal so shakes his sense of honor that he decides to live in the wild, like an animal. There he joins up with a motley group who are illegally mining the shogun’s gold, and, with the aid of another swordsman, gets a chance not just at survival but to recover his name and honor.

Yoshinari Bessho, the feudal lord of Tanba Province, is a collector of butterflies and has his concubines tattooed with butterflies as well. One day while hunting, Yoshinari sees Gennosuke Akizuki's beautiful wife, Okoto. He kidnaps her, tattoos a butterfly on her shoulder and takes her for his own. Feeling shame for what has happened, Okoto throws herself into a well and commits suicide. She then returns as a ruthless ghost that seeks revenge against Yoshinari and his retainers. Whenever the ghost appears, mysterious butterflies always fly around her...