Japan is a settler society, they colonized and displaced the indigenous Ainu and Okinawans. And Japan is multicultural. You might be forgetting that different

Japan is a settler society, they colonized and displaced the indigenous Ainu and Okinawans. And Japan is multicultural. You might be forgetting that different Asian cultures exist, or for some reason conflating "culture" with race and ethnicity. Much of what people consider to be "Japanese culture" originated in China or Korea, and that isn't even taking into account nearly a century of westernization. Also no one is forcing anything onto anyone.