There were once three princesses: Princess Allie, Princess Mellie and Princess Libby.
Being a princess is wonderful - not only do you wear gloriously extravagant gowns every day, but you also have beautifully elegant hair AND you are particularly pretty, too. But today the princesses are arguing over who is the prettiest of all, with each princess claiming that it's her.
How can they settle the argument? With a beauty contest, of course!