Errol and his teddy, Thomas, are best friends who do everything together. Whether it's riding a bike, playing in the tree house, having a tea party, or all of the above, every day holds something fun to do. One sunny day, Errol finds that Thomas is sad, even when they are playing in their favorite ways. Errol can't figure out why, until Thomas finally tells Errol what the teddy has been afraid to say: "In my heart, I've always known that I'm a girl teddy, not a boy teddy. I wish my name was Tilly, not Thomas." And Errol says, "I don't care if you're a girl teddy or a boy teddy! What matters is that you are my friend."