Crypto currency French citizenship

Hi everyone,
Im French and living in Japan under a work visa. Ive been looking at getting started with crypto currencies and a lot of people around reddit advise to create an account in my home country instead of Japan, as Jp has a high taxe rate and doesnt allow to offset losses.
Im trying to weight the pro and cons, and figure out if since Ill be taxed in Japan on my global income/asset gains. Could anyone share his experience ?
Cheers !

by moelil