A socially awkward but very bright 15-year-old girl being raised by a single mom discovers that she is the princess of a small European country because of the recent death of her long-absent father, who, unknown to her, was the crown prince of Genovia. She must make a choice between continuing the life of a San Francisco teen or stepping up to the throne. While Mia makes up her mind, she's pressed into taking princess lessons from her grandmother.