A phonics-based story for readers in kindergarten through grade two in which Rosie tries to get her grumpy brother Clay to play dress-up when he only wants to play ball.

Bill and his little sister Kay enjoy playing in a big box, which becomes in turn a car, a jet, and the engine of a train.

Simple text about fun things and repetition of the letter 'u' help readers learn how to use the 'short u' sound.