Just because they stopped carrying katanas everywhere doesn't mean they stopped being Japanese.

Just because you can find a few Macdonalds' there, doesn't mean they turned American.

European economic policies don't make the country European, it's just that economics was mainly developed in Europe and America.

And just because they embrace some beliefs of Americans doesn't make them
American; I don't suddenly turn Japanese if I start sleeping on the floor and taking off my shoes before entering my house?

Just cause they went through some changes since the end of the Tokugawa Shogunate doesn't mean they are no longer who they are: change is inevitable.