In an article I came across on boingboing I came across this imagery,whereas Musti was designed a few years prior to Kitty apparently. The original source blog quoted the following:

Kitty’s design was just a crib from this!!!
This is “Musti” created by the Belgian animator/director Ray Goossens (1924-1998). Musti was started as an animation series on TV in 1968, and its picture books were also published. I read some of that books and loved it in my childhood.

There were a variety of the usual naysayers and claims made how Hello Kitty was a rip-off etc. etc. of course some of them claimed that Musti was a rip off of Miffy by Dick Bruna.

The resemblance is rather uncanny, but often people will create a big story for sensationalist reasons. Sure, Musti and Kitty have some similarities, but the very original Hello Kitty design looked like this:

Compared to the above image, doesn’t strike me as “close”. Could the original artist have been inspired by the design of Musti (or Miffy). Maybe, it’s not unheard of but there is such a thing as the court of law, and if indeed Musti had a serious chance in claiming the copyright they would have done so already.

Infact, Musti and Miffy are far closer, given the X for a mouth, and the overall design qualities. The fact that Kitty-chan has no mouth is now almost a trademark legend (why does she now have one anyway?). Besides, I think that Kitty-chan is much much cuter (and adult in design) than both Musti and Miffy, Musti has a decidedly jagged kindergarden look intentionally crooked to resemble the image of the drawings of a very young child or toddler. Their target audience is also very different.

To conclude, in the compounds of art and design, I think Kitty-chan is original creation in my view, what do you think?