Switched at First Kiss

It begins with a kiss between Summer Moore and Sheldon Hall, and after it the two of them are in each other's bodies with no way back. They have to go on living each other's lives, which most people around them would call a disaster. Summer had wanted to be an actress. In Sheldon's body she finds herself nearer to that than she had ever managed on her own, and it is Sheldon, going about under her name, who reaches it. He finds his new life lighter than the one he had, with a freedom in it he was not used to, and he turns cheerful and easy about things. Summer takes some of that from him and starts studying and working on herself. Running each other's days puts the two of them in the habit of relying on one another.