There is a very serious risk associated with trading on exchanges.

If an exchange suddenly updates its KYC rules, and you can no longer meet those requirements (for whatever reason), then your funds will be permanently seized.

Good luck to any foreigners trying to get BTC out of Bitflyer in Japan.

My BTC on Bitflyer has been seized for over a month, with seemingly no way to withdraw it in any form, and no explanation from Bitflyer (they haven't answered my last 5 messages).