Most tragedies follow a basic template. A protagonist begins in a certain place - whether it's a normal steady place or immediately after something difficult has happened to them - and they encounter some sort of disaster that throws their world into chaos. The rest of the movie is spent dealing with that chaos, and the protagonist eventually either recovers or succumbs to their challenges in some way. A good recent example of a typical tragedy in the Collection is Secret Sunshine. A woman moves to her deceased husband's hometown to raise their child there when something horrible happens that propels her forward through a spiritual and existential journey. There are multiple heartrending moments in the film, but - like the majority of similar movies and stories of any kind - it's the one central tragedy around which the film revolves.
The Life of Oharu has perhaps ten, maybe even fifteen moments like this. Oharu is betrayed, misled, punished, humiliated, and victimized by random fate so frequently in the film that Mizoguchi's portrait nearly collapses under the weight of absurdity. Mizoguchi's steady hand and the main performance of Kinuyo Tanaka, who worked frequently with the director (she's in all of his films in the Collection), ultimately save the film from the type of sensationalism reserved for similar exploitation movies disguised as social commentary (see: Precious), but the comparisons are still evident. While Mizoguchi has honorable intentions, his portrayal of the plight of women in Japan has little of the complexity and sharp bite of Imamura or Oshima. This is mainly because the film is so melodramatic that it doesn't feel real, the message so obvious that it's hard to take away any applicable lesson.
By the way, this movie is really, really good. I know it doesn't sound like I think that, but it's beautiful and humanistic and it's impossible not to feel a strong attachment to Oharu. Each story within her journey ranges from moderately interesting to stirring enough to be the basis for its own film. And like Mizoguchi's poetic masterpiece Sansho the Bailiff, the film's imagery is lyrical and indicative of Japan's beautiful visual iconography. It's just that when you're finished, you're going to need a long bath.