Good to know that the Chinese exchanges don't have a monopoly on Bitcoin trading.
Japan may be number one now in volume but Chinese exchanges enjoyed a highest volume for a long time and i know in future they will retain the highest volume again. Seeing other countries like Japan in the Race with china in Bitcoin adoption is sure a healthy competition for bitcoins overall.
Those high volume was fake. You can see how fake it was when those big exchanges implemented fees on trade transaction. But yeah, I agree that world wide adoption and competition is healthy for Bitcoin economy. As far as I know Japan is more Bitcoin friendly than China.
The popularity of bitcoin in Japan started evolving last year as there was a growing demand for bitcoin and things might even change in Japan in the future as there are rumors that Japan is planning to legalize bitcoin as a currency. There may be new rules and regulation coming up and really looking forward to how the future holds.
It's kind of strange how advanced Bitcoin has been getting within countries like Japan and a lot of other countries in Asia as well. I don't mind it at all to be completely honest, and something like what we have now is fine by me.
I'm more surprised that China is not longer leading in volume though, they were on top for essentially the existence of Bitcoin since 2013 iirc.