Summer is over, and Sarah can't wait to start school and make some new friends other than her rotten cat, Ralph. But Ralph wants to be Sarah's only friend, and he won't be left behind. When Sarah boards the school bus, he disguises himself as a student, follows her to class, and starts his scheme of sabotage. Ralphs plan works brilliantly until his true identity is revealed and the entire class wants to be friends with Sarah and Ralph!