This is how it come out based on my reading of the Wikipedia article:
1) The “Maneki-neko” is a sort of good-luck omen, but is not worshipped itself. At most, it is treated as if it can tell the future and I’m pretty sure that nowadays, the vast minority of people who have it displayed do it just for show (and don’t believe it has any “powers”)
2) There is NO evidence that Hello Kitty is based on this Maneki-neko. The first picture looks somewhat similar to it; that’s because it’s a cat, and Hello Kitty is also a cat.
I’ve actually seen the waving cat thing several times in the windows of (non kosher) Chinese restaurants, and always have seen it golden. That really looks nothing like Hello Kitty.
3) Even if I agree that Maneki-neko is an Avodah Zara and that Hello Kitty is based on it (which I’m not prepared to do), Hello Kitty would only be based on it, not being another version of Maneki-neko.
4) Finally, let’s say Hello Kitty was designed to be an Avodah Zara.
Now, there are a lot of crazy people out there, but I have never heard of anyone ever worshipping Hello Kitty. Does it have the halachic status of Avodah Zara if it was never worshipped as such?
Have a good Shabbos.