Sansho Dayu is (along with Ugetsu Monogatari,) quite simply a masterpiece of Japanese (and indeed world) cinema. Sansho Dayu (and Ugetsu Monogatari) are frequently top (or near the top) of serious critics' lists of the best movies of all time. This movie is the tale of the sad fate of a brother and sister following the murder of their father and separation from their mother.
Mizoguchi is one of the gods of Japanese cinema; Ozu poignantly depicted the distances between generations and the changing face of the family in 20th century Japan but the principle concern of Kenji Mizoguchi was how women have suffered in a male-dominated society throughout Japanese history. This heartfelt theme was almost certainly instigated by his father's brutal treatment of Mizoguchi's mother and sisters and the eventual selling of his older sister into the life of a geisha. Often in his films women suffer terribly as a result of inflexible social rules and hierarchies. Watching them, however, is continuously rewarding. This movie is poignant and tragic but it is not depressing to watch; here is a director at the top of his game.
Part of what makes these movies so outstanding is Mizoguchi's artistic use of the camera with perfect composition, framing and meticulously executed long takes. Watching this movie is a reminder of how, for many of us, black and white film has a quality which is essentially cinematic and part of the enjoyment of the experience. Mizoguchi's use of lighting and composition shares all the luminous formal beauty of Japanese art.
And then there is the story itself, with its unforgettable final scene.