Yuko Shimizu is Hello Kitty's original creator. She was born in Chiba Prefecture, Japan on November 1st, 1946. She graduated from Musashino University and then went on to work for Sanrio until 1976 when she retired. Now Shimizu is a freelance designer and continues to design characters similar to the famous Hello Kitty. Many of Yuko's designs are based off pets she has had in real life that were significant to her in some way. Kind of like one of her more recent characters, Angel Cat Sugar who is based off of a stray white cat that lived with her for a while. The idea of Hello Kitty came at age 36 from Shimizu's white bobtail cat.
Yuko Yamaguchi is Hello Kitty's third, current, and most significant designer. She was born is Kochi Kochi, Japan and studied industrial design at Joshbi University of Art and Design. Since joining Sanrio in 1978, Yamaguchi has been Hello Kitty's designer for most of her history. Yuko says in an interview that she thinks Hello Kitty is a part of her, and whatever Kitty does, she does and vice versa. She believes that because of Hello Kitty's simplicity, she is easy to work with and loves to see different renditions of her created by fans and designers. Yamaguchi changes Hello Kitty's designs with the seasons and applies her to many different trends and styles to appeal to as most people as possible and to keep Hello Kitty trendy and admired.