If you've never heard, seen or worn "Hello Kitty," you may have been living in a cave over the past decade. Hello Kitty has become an international fashion and marketing phenomena, spanning every continent and breaking sales records in department stores around the world. But exactly who is this adorable, mouth-less "kitty" that has captured the hearts and minds of so many adoring fans?

Hello Kitty was originally created in the 1970's by Japanese company Sanrio, and is the company's most famous fictional character. The kitten-like animation

was originally developed under the name "Kitty White," but this name was never used commercially. The character was first marketed in the United States and

has been an unofficial ambassador for the charity, UNICEF since 1983.

The Hello Kitty brand became much more prominent during the late 90s when celebrities began adopting Hello Kitty fashion in their wardrobes, with Mariah Carey being one prominent example.

Today Hello Kitty Merchandise stocks the shelves of nearly all American department stores and the Hello Kitty character has even been featured in advertising campaigns buy retail giants like Target in the US. Products such as Hello Kitty bedding, the Hello Kitty wrist watch line, and the much sought-after Hello Kitty digital camera are just a few of the plethora of goods offered in a Hello Kitty version.

Among American celebrities sporting the Hello Kitty brand, Cameron Diaz, Carmen Electra, Heidi Klum, Christina Aguilera, Steven Tyler, Mandy Moore, and Raven Symon? lead the list. Paris and Nicky Hilton have also been photographed wearing the Hello Kitty brand, as has pop-singer Lisa Loeb, who is currently promoting the hot-pink "Hello Kitty guitar."

Females are by far the largest market for Hello Kitty products. And at times it seems their appetite for Hello Kitty products is insatiable. There's a new Hello Kitty Robot, for example, equipped with both face and voice recognition, and the ability to dance around while talking to its owner. And let's not forget the newly-released Hello Kitty debit card.

Nearly any product you can think of has (or soon will be) branded with the Hello Kitty logo. But what is really behind this worldwide obsession? What exactly is the appeal of Hello Kitty, especially to females?

Part of the answer could lie in the mystery of Hello Kitty's back-story. Kitty appears to be asexual and his/her character profile is kept vague -- this allows fans to attribute any characteristics they like onto Kitty, instilling the character with their own values, emotions and backgrounds.

Not only does Hello Kitty appear to have no distinguishable sexual characteristics, it also has no obvious ethnicity. Fans tend to "adopt" Hello Kitty into their own ethnicity, age group, likes and dislikes, and perhaps that's part of Kitty's charm.

As you would expect, Hello Kitty does have an official bio, but it appears vague almost to the point of being mysterious. In any case, the huge worldwide success of the character does not seem affected in the least by what we know about him/her.

As Kitty is fond of saying "You can never have too many friends." And with a world wide branding juggernaut that has made inroads in every major market across the globe, Hello Kitty will likely never have to worry about not having

enough friends.