Of course, not all Japanese movies are about hopelessness, but the cultural situation for Japanese and Chinese is rather bleak like German culture.
Their drama has at its base a powerful sense of futility, and the proposed solution is that one simply endures and suffers because death is thought to be something worse.
It is only in strongly Christian societies that hope is the foundation of human life. Even Jewish life, while not hopeless, tends to see life as more trial than joy. All other religions end in fatalism.
I'm willing to bet I've watched a lot more Japanese movies and tv shows than you and honestly the idea that "life is just something to endure" is no more true of them than of us. I understand what you're saying, that without a proper hope based in Christianity things are empty, but as far as movies or things go, it's pretty much the same, culture to culture.