Have you ever noticed that Hello kitty hasn’t got mouth? Its designer, Yuko Yamaguchi, made it on pourpose. “I want people to be able to project their feelings on her. Kitty looks happy when people are happy and she looks sad when people are sad” –  Yamaguchi says – ” If she had a mouth, she would have an expression and nobody could find in her his mood, so I preferred to paint it not.”

Sources: http://slowbuddy.com/photography/hello-kitty-pictures/

  (in Italian)  http://it.wikipedia.org/wiki/Hello_Kitty