From The Grindhouse Cinema Database
Chambara Films (an onomatopoeia describing the clash of swords) are a revisionist, non-traditional style of samurai film that achieved popularity in Japan. Its origins can be traced as far back as Akira Kurosawa, whose films feature moral grayness and exaggerated violence, but the genre is mostly associated with 1970s samurai manga by Kazuo Koike, on whose work many later films would be based. Chambara features few of the stoic, formal sensibilities of earlier jidaigeki films – the new chambara featured revenge-driven antihero protagonists, nudity, sex scenes, swordplay, and blood.
Yakuza Films are post feudal period action films which focus on the lives and dealings of yakuza: Japanese organized crime syndicates. (Wikipedia)