Japan has a significant adoption of BTC. But ultimately the fuel for BTC will most likely be the interest in other projects as the majority of coins are traded against BTC. I think a lot of the newer coins are taking adoption a bit more seriously than BTC right now as BTC has been focusing on upgrading tech rather than adoption mechansims. As more coins adopt fiat/coin pairings BTC will start to stumble but until then I am bullish long term.