Japan still remains as the largest bitcoin exchange market with over 51 percent of the market share, analysts stated that the crackdown on small exchanges have had an impact on the global cryptocurrency market
Yes, you are right. Japan is one of the leading countries in adopting bitcoin in the country. a progress that should be imitated by other nations. it's just a matter of time waiting for bitcoin to be the main alternative payment tool in the world, accompanying the major currencies of the world as a means of payment received by all parties.
But if you want to know the country that still prohibits bitcoin in the country you can find out the information in this link.
https://www.ccn.com/top-10-countries-bitcoin-banned/kind regards.