Sometimes, people ask me the question. Then I say, “How do you define Japanese?”
Others say, “It's your parents. If your parents are Japanese, you are Japanese.” Then I say, “How do you know your parents are Japanese?” The question goes to the beginning of the human history. Then, you will see that you are not Japanese at all. Probably, you are African!
I used to think it's appearance. If you look like majority of people in Japan, you are Japanese. This criterion probably worked 200 years ago but not anymore.
Several years ago, I met a guy who looked totally Japanese, not Koreans, not Chinese. I had no doubt about it and talked to him in Japanese. I couldn’t communicate with him because he didn’t speak Japanese at all. It turned out he was a third generation of Japanese American.
Since then, I’d been searching for an answer to this question, “What makes someone Japanese to me?” Recently, I got the answer from one of my American friends.
He said, “It’s the language." I thought his answer was brilliant. It’s the language not the appearance that makes someone Japanese to me.
Now, if someone asks me, “Are you Japanese?” I would say, “Why bother?"