Hello, nonie. Honestly there's no special meaning behind it, so instead, I'll tell you how did I end up with this name. Last month, I tried to find an OC name for fun. I wanted it to be related to ocean, I found "Kai", which has the meaning "ocean", but I didn't really like the name. Few days later, I watched a japanese horror movie titled Kairo (2001) with a friend. Then I remembered, I was looking for an OC name before. I thought Kairo was a good one, and surprisingly, I liked it? (It has "Kai" in it, too!). That's how I got the name Kairo for my OC name! :)