In a series of humorous diary entries, a New York City ninth grader agonizes over her love life, final exams, and future role as the princess of Genovia.

Princess Mia's junior year in high school begins with a difficult course load, a crazy student council race, Grandmere's search for temporary lodging, and learning that her boyfriend is moving to Japan for a year, partly because she will not sleep with him.

Fourteen-year-old Mia, who is trying to lead a normal life as a teenage girl in New York City, is shocked to learn that her father is the Prince of Genovia, a small European principality, and that she is a princess and the heir to the throne.