Japan: Hotel Bans?

I was reading about Japan, when I came across something that said there was a semi-ban for women to enter a capsule hotel. Wanting to know more about this, I will do more research. This ban is semi because there are hotels that accepts women. Most capsule hotels depending on the location, are men only I read and doesn't allow women though. Whatever city, I will have to know if they accept women now. It wouldn't be quite fun sleeping outside in a different country because of this reason. Since my family's travel is not just a visit in Japan, but a move, it would be similar to being homeless. That is until we get a house. This will be an interesting experience...