"Umeko and Kuwa" is a Japanese story read by Hiroshi to Bob and the kids on Sesame Street, with Oscar and Slimey listening in. (First: Episode 2459) It's the tale of Umeko, a little girl who has a silkworm named Kuwa for a pet. Her friends sometimes make fun of her for having a pet worm rather than a dog or a cat.
By this time, the day of the great Japanese festival is approaching. Unfortunately, Umeko has nothing to wear but her ragged, old kimono. She dreams of having a beautiful new one. When she wakes up, her dream becomes a reality, because Kuwa has gone into his cocoon and come out again transformed into a moth. And in return for the kindness Umeko has shown him, he lets her use the silk left over from his cocoon to make herself a new kimono. Umeko does just that, and her friends at the festival are astonished. She tells them the moral of the story: friends are always beautiful.
Sesamestreet.org lists the skit as "The Story of Umeko and Kuma."