Plot
In the kingdom of Gardania, teenage Blair Willows works as a waitress at a small café to support her sickly adoptive mother and younger sister Emily. Returning home, Blair is shocked to find out via a televised broadcast that she has won a lottery for a scholarship to become a Lady Royal—a princess's advisor—at the prestigious Princess Charm School, a magical academy where princesses from different kingdoms are educated. Emily reveals that she signed up Blair for the lottery multiple times to ensure her selection. Despite Blair's reluctance, her mother assures her that attending the school is a good opportunity.
A carriage comes and takes Blair to the school, where she is enthusiastically greeted by a golden retriever named Prince. Blair meets Headmistress Alexandra Privet, who tells her that every student is assigned a fairy to act as their personal assistant. Blair's fairy, Grace, takes her to her dorm where she meets her roommates: Princess Isla, who mixes electronic music, and Princess Hadley, an avid sportswoman. Blair is also introduced to Dame Devin, sister-in-law of the late Queen Isabella, sister of the late King Reginald and Devin's daughter, Delancy, who will be crowned princess and ruler of Gardania at the school's graduation ceremony. Blair struggles in her classes due her clumsiness; and is further hampered by Dame Devin and Delancy, who take a strong disliking to Blair and make several attempts to sabotage her. Blair perseveres and improves when she receives special tutoring from Headmistress Privet.
While exploring the palace, Blair and her roommates happen upon a portrait of a young Queen Isabella and note her striking resemblance to Blair. Upon seeing another portrait depicting the late royal family (including Prince as a puppy) and learning that Blair was found by her adoptive mother on the same day the royal family died in a car crash, Isla and Hadley deduce that Blair is Queen Isabella and King Reginald's long-lost daughter, Princess Sophia, and the true heir to the throne. This discovery is overheard by Delancy. At dinner, Dame Devin announces her plan to demolish the poorer neighborhoods where Blair's family lives and replace them with new parks. However, she attributes this plan to Delancy, who appears conflicted.
Blair almost decides to return home, but changes her mind and becomes determined to find the legendary crown of Gardania, which is said to glow when worn by the rightful heir. On the night before graduation, Dame Devin plants jewelry in Blair's room and accuses her and her roommates of stealing. The three of them are then ordered detained, but are saved by Delancy, who does not want to usurp the throne from the true heir. Blair, her roommates, and Grace sneak into the palace vault, but are caught by Dame Devin, who takes the crown and locks the girls inside.
The next morning, Delancy attempts to stall her coronation, giving Isla enough time to deduce the vault code, allowing the girls to escape. Blair arrives at the coronation and makes a claim to the throne; she, her friends, and Dame Devin struggle to grab the crown, which eventually falls into Delancy's hands. To her mother's dismay, Delancy places the crown on Blair's head. The crown glows and magically dresses Blair in a new gown, confirming her identity as Princess Sophia.
Dame Devin angrily berates her daughter and inadvertently reveals that she orchestrated the deaths of Queen Isabella with King Reginald and her family so Delancy could inherit the throne. Dame Devin is arrested, and Sophia elects Delancy as her Lady Royal. At a celebratory dance party that evening, Sophia is reunited with her adoptive family.
