Just putting our name out there, I figured a few people here may be interested, I help run a forum dedicated to the heavy metal and hard rock groups of Japan in all its eras, there's discussions about all kinds of bands, from X Japan, Dead End, Loudness, etc. to Dir en Grey or various touhou/doujin bands. We began about 4 months ago and so far have 109 members, and nearly 12,000 posts, a growing wiki on Japanese metal history, interviews with Japanese musicians, reviews of albums, and a growing marketplace.
If you're a Japanese metal fan, or are merely curious about Japanese metal, feel free to come check us out at jpmetal.org