In Japan there something called Pachinko http://en.wikipedia.org/wiki/Pachinko with parlors everywhere. It's basically like slot machines (pokies), but with little ball bearings and maybe a little more skill. It took me a while to work it out, I still don't know the full story, but it's something like this:
Gambling with Pachinko is illegal in Japan.
Pachinko parlors can't pay you directly for your balls but give you tokens instead.
There just happens to be a separate establishment near every Pachinko parlor called a Kiosk (always seems to be written in English) which for some reason happens to have an interest in purchasing little tokens.

Bitcoins are legally a commodity of perceived value similar to those tokens. Any gambling with bitcoins would currently be perfectly legal.