I hope you had a good weekend! The wife and I had dinner with some friends that we've known for ages. One of our friends married a Zainichi Korean, which caused a huge stir with her family. It was so bad that her father almost disowned her and cut off communication until the birth of her first child.
Like most Koreans living in Japan, her husband has a Japanese last name to avoid discrimination and blend in with society better. He's not a citizen, and our friend told us of her surprise the first time she saw her husband's alien registration card (which all foreigners in Japan are required to carry.) Her husband was born in Japan, doesn't speak Korea and hasn't even been out of the country!
With we were having dinner and getting totally shitfaced, I remember him saying, "But I'm not Japanese" when he was teasing his wife about something. My wife and I have never discussed him being a Zainichi. There are minorities in Japan like burakumin, but unless you can physically see they are different, it's just not discussed. This was the first he'd mentioned it to us, and he doesn't know that we know. My wife and I were wondering if he was finally getting comfortable enough to open up -- even if it was just an off-hand remark on his part.