Hello Kitty was a 1974 Japanese creation, and the character first showed up on a coin purse. It was brought to the USA in 1976, and by the 2010's, was making 7 billion dollars per year without advertising. Although popular in the 80's, seeing as how you could buy plush dolls, stickers, erasers, figurines, coin banks, make-up stuff, alarm clocks, and just about anything else you can think of, the toy line really began accelerating in popularity in the 1990's.
In 1987, the first Hello Kitty cartoon was released (Hello Kitty's Furry Tale Theater), and several more have been released post 1980's. By the early 1990's, Hello Kitty began showing up on video games as well.