Where are you seeing Japan as #1 in volume? Looking at
http://data.bitcoinity.org I'm seeing these volumes for the past couple weeks:
Volume (in BTC) | Week 7/23 | Week 7/16 |
USD/BTC | 621k | 982k |
CNY/BTC | 180k | 255k |
JPY/BTC | 94k | 168k |
Looks like Japan's volume is still way behind both China and the US.
I guess Japan had its time on the first spot sometime in February. But we can really see the aggressivess among these countries and how competitive they are in every aspect of country rivalries that we see even in bitcoin world. Like I've said in other threads, whatever the US started, its rival countries will always try to cope up and compete.