I know Hello Kitty has fans. In fact, I have to admire Sanrio for creating a sort of Seinfeld of cuteness.; Hello Kitty really isn't about anything. Hello Kitty is sort of a brand of general adorable cuteness and pathological amounts of pink. It's just that when it comes to it, there's not a whole lot of "there" there. Hello Kitty just sort of is.
She's darling, as is her collection of friends, but she's not about anything.
Sanrio's success aside, you don't want to use her as a role model for personal branding. Even if you like Pink. A whole lot of Pink.