The same thing that's interesting about most foreign countries' cultures. It isn't the same as ours, so it's interesting. I love the USA and I have no plans on moving from here or anything, the Japanese just happen to have a pretty interesting culture. When I first started college and had to pick a language, incidentally, I wasn't even into anime and everything, I just picked Japanese because it looked harder than something that uses a regular alphabet and I wanted a challenge.