Hello Kitty is a popular Japanese character. It is a literal modern translation of 'Maneki Neko' or, the 'Beckoning Cat' which is a symbol of welcome and is used in many Japenese/Chinese store entrances. Sometimes Maneki Neko has his left paw up, sometimes the right. The left paw signifies that the business owner is inviting in it's customers. The right paw invites in money or good fortune. Most Maneki Neko's are calico cats; the male calico is so rare it's considered lucky in Japan But Maneki Neko may be white, black, red, gold, or pink to ward off illness, bad luck, or evil spirits and bring financial success, good luck, health and love. Maneki Nekos made in Japan show the palm of the paw, imitating the manner in which Japenese people beckon. North American Maneki Nekos show the back of the paw, imitating the way we gesture 'come here.' The higher Maneki Neko holds his paw, the more good fortune is being invited.
According to legend, that cat, called Tama, lived in a poverty stricken temple in 17th century Tokyo. The temple priest often scolded Tama for contributing nothing to the upkeep of the temple. Then one day, a powerful feudal lord named Naotaka Ii was caught in a rainstorm near the temple while returning home from a fishing trip. As the lord took refuge under a big tree, he noticed Tama with her paw raised, beckoning to him, inviting him to nter he temple's front gate. Intrigued, Naotaka decided to get a closer look at he cat. Suddenly, the tree was struck by lightening and fell on the exact spot where the lord had just been standing. Tama had saved his life! In gratitude, Naotaka made the little temple his family temple and became it's benefactor. Tama and the priest never went hungry again. After a long life, Tama was buried in gratitude at the Goutokuji temple. Goutokuji still exists, housing dozens of statues of the Beckoning Cat.
Hello Kitty is the modern version of this, so many kids have good fortune (probably)
Source- Uncle John
's Unstoppable Bathroom Reader