There are definitely guys who don't mature...my cousin dated and married one for awhile.
You know there is something wrong about a 30+ yr old man who still thinks fart jokes are funny and pigs out at the dinner table...not to even mention the fact he's the guest no less.
On the other hand the same goes for women. So there are just PEOPLE who don't mature.
All this being said, as a stranger in a strange land I'd have to say that Neko-Chan does come off as a little crazy, but in a good way lol.