Forgive me for saying so, but the information posted here and in the Hedorah/Gigan/Ebirah thread is somewhat erroneous.
The Japanese use the same video levels as everyone else (16-255), and messed up black levels are not something that are unique to Japanese discs.
This misconception comes from the analog/SD days. The IRE standard in Japan (and Europe) was 0, whilst North America used 7.5. This did result in discrepancies when viewing Japanese produced video, which had to be compensated for, but is completely irrelevant today.
That's not to say that there aren't any issues with transfers like Godzilla vs. Biollante (the Echo Bridge disc anyway). That one is a prime example of messed up black levels, but to suggest that it's a problem to be found across all Japanese Blu-rays and many US discs using Japanese transfers is completely wrong.
What the actual issue here is discs being made to conform to PC video levels (0-255), instead of studio levels (16-255). Your TV (whether you're in the States, Japan or Europe) is made to output black based on studio levels. But if a transfer is done to PC levels, the blacks end up washed out on your TV. There are plenty of US and UK Blu-rays of films with no connection to Japan whatsoever that suffer from this problem. There is a list in the following link, with some further details on this problem:
http://www.avsforum.com/t/1496542/blu-r ... -pc-levelsCase in point, whilst the Echo Bridge disc of Biollante looks awful and completely washed out, the original Japanese Blu-ray looks fine. There are some caps of it here (displaying on a non-Japanese TV):
http://www.avsforum.com/t/1181538/all-g ... t_17422210Compare the opening credit cap to this one from the Echo Bridge disc:
http://www.blu-ray.com/movies/screensho ... position=6So yes, certainly discs like Biollante need compensating for as described in the post above, but don't do it automatically just because your Blu-ray is from Japan or your US disc is using a Japanese transfer! Most of these are fine. I have the Studio Ghibli Japanese Blu-rays myself and they're perfect.