Recommendations to find old Japanese music

I'm not talking about your big names but some very obscure ones that have only a few releases in the 90s.

I can find the listings on big name stores' websites but it's always the same. No stock and discontinued. I found some one e-bay but the prices are crazy.

I am hoping someone here has recommendations to some older obscure stores that might still carry them.

1890s? Did they even have `78s back then? (OK, lame joke...)

So 1990s. If you are in Japan, I would contact `Hard-Off` and any other `recycle shops`. Maybe register your desire, name and phone number (if they do this). For really obscure stuff, maybe even look thru the boxes at the Nissan Stadium and Ajinomoto Stadium (both Tokyo) flea markets, and ask the dealers to be on the lookout for you. If not Tokyo, then similar events/shops wherever you find them.

You can see releases from the 1980s, 1990s, and early to mid 2000s in Book Off all the time, especially the larger ones, like Akihabara or Shibuya in Tokyo.

If the acts are obscure in the first place then there is not much chance of them being in Book Off, Disc Union would be a better bet http://diskunion.net/