Lizzie McGuire prepares for her junior-high graduation with one of her two closest friends, David "Gordo" Gordon. Her other best friend, Miranda, has chosen to skip the graduation ceremony in favor of a trip to Mexico City to visit her relatives. During the ceremony, Lizzie trips onstage and accidentally brings the curtain down on her fellow graduates; this causes her to be teased by her younger brother Matt and her former best friend Kate Sanders. After graduation, Lizzie and some of her class embark on a trip to Rome, chaperoned by their future high school principal, the rude and stern Angela Ungermeyer (The rest of the class chose a trip to a water park instead). To their dismay, Lizzie and Kate are assigned to the same hotel room.