My issue here does involve Gaming Club Japan. Bear with me as this might be a long post
Why mention "Belle Rock" and not specifically "Gaming Club Japan"?
1) So as not to cloud the key issues, which are winnings being denied with no justification & nonsensical (and seemingly unmeetable) demands for ID. If the casino/Belle Rock say they're refusing to pay because this isn't a separate casino that becomes a different issue (ideally with it's own thread). The last two pages of this one plainly demonstrate why it was better to stick to Belle Rock for now.
2) This doesn't involve only Gaming Club Japan players - it's a Belle Rock-wide issue
3) It's perfectly normal to refer to Belle Rock when complaining about one of their casinos. That's been standard practice for a long time on Casinomeister and it's clear that poor CS and suspect policies don't vary much from casino to casino.
Note that Spearmaster himself even after bringing this up has been doing the same:
spearmaster said:
Now, having said that, WTF did Belle Rock not:
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Not going to argue with that point, I certainly do not agree with how Belle Rock handled that under any circumstances.
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However, if they have another Gaming Club account, then Belle Rock...
Gaming Club Japan is a separate casino
This is clearly not just a separate website interface to the same casino. Some evidence:
1) As Grandmaster mentioned they have separate PWC reports: e.g. US/UK
(pick Feb 2006 & note both US and UK websites link to this report) - Japan
2) This is Casino City's take:
Link Removed (invalid URL)
3) If that doesn't convince you, here's Belle Rock themselves (or their affiliate managers):
Gaming Club Japan was established in a different year, has a different manager, different software and separate reports on its games. It's a distinct casino, like Intercasino US is distinct from Intercasino UK (and note it's fine to play at both). The UK and US links on the Gaming Club website, on the other hand, just provide a different entry and different bonuses for access to the same casino.
Why play at Gaming Club Japan?
Why play at more than one Microgaming casino? I imagine we all have our reasons (variety, bonuses, a gambling problem), but I don't think it's common for people only to play at one site, however much they trust it.
I've played at French, German, Italian and Russian sites (Goldfishka is a personal favourite, and yes, if I had an issue there I would bring it to Fortune Lounge). It's true I can more or less read all of those languages, while my Japanese is a little rusty (

though I can read a few Chinese letters...), but it's really not difficult to understand the same software in any language - I can't say I play casino games for linguistic enrichment, though the Japanese symbols are pretty funky!
As mentioned, the terms and conditions are in English (in fact the English terms take precedence over those written in Japanese). The UK is listed as one of the locations you can play from when registering. I realise I'm not the main target for Gaming Club Japan marketing, but I see no reason whatsoever not to play there.
Conclusion
Sadly, playing at Gaming Club Japan is almost certainly not the issue here (if it was players could argue an extremely strong case for being paid). But if it was then why would Belle Rock and eCOGRA be refusing to explain their decision? Why would players be being led on a wild goose chase to provide documents? And why would people who've played at other Belle Rock properties be having the same difficulties?
We still haven't got anywhere close to the bottom of this.