Sô Yamamura is the head of an institute for treating and reforming prostitutes. The 'White Beast' is syphilis, a disease which understandably terrifies the inmates. Over the course of the movie, one goes mad from tertiary syphilis, another is diagnosed with it, and one finds out she is pregnant and insists on having the baby. Yamamura and his staff treat the girls compassionately, trying to deal with their conditions, medical and spiritual and maintain a positive, uplifting, professional attitude throughout.
Director Mikio Naruse makes fine use of the techniques of storytelling to offer the problems in context -- that's why one of the girls is terminally syphilitic, while one is newly diagnosed; it allows the movie to show the stages of the disease almost simultaneously. However, the movie is more didactic than story. It is Augustinian in its philosophy, holding that sin arises from error, rather than nature. It presents prostitution as a problem that can be solved humanely, and not by lecturing people on right and wrong and insisting that people who do bad things can change, repair themselves, and become good people. The movie never indicates that it is easy, but that it is possible.
