Which is why I find that this footballing culture in Japan (much less in Korea) is 'fake'. There is never a strong culture to begin with and it is sad to see these fans, who were never fans of these countries anyway, paint their faces, shout chants and cheer their 'adopted' teams during the game. There are some real Japanese fans who really supports the teams, but we are not seeing a lot of them.
Perhaps we can find a whole hoard of Japanese fans who paint Senegal or Costa Rica's flag on their faces and ask them if they know anyone from their 'team'. That should give you an answer.
I do not meant to be insulting or rude, but this is just how I feel.