Princess Punie Tanaka of Magical Land must complete a single task to earn her right to the throne: she must survive as a transfer student at a Japanese high school. The catch is that her potential coronation makes her a target for a steady stream of assassins, rivals, and chaotic troublemakers who all want to stop her reign before it begins. Punie may look like a sweet, innocent magical girl, but she responds to every threat with a jarring combination of ruthless martial arts, overpowered magic, and a hair-trigger temper that turns even the most trivial school event into a battlefield.

The series takes place in a mundane Japanese town where Punie tries to navigate everyday high school life while constantly fending off attacks. Despite her violent methods, she is the heir to the magical kingdom and is accompanied by her bizarre mascot Paya-tan. Her younger twin sisters, Pyon and Potaru, repeatedly attempt to assassinate her to claim the throne themselves, though their schemes always fail. Other recurring enemies include the vengeful warrior Elise von Barbaroque and the school delinquent Anego, whose ordinary conflicts with Punie escalate into absurdly brutal confrontations.

The manga is built around episodic arcs that parody classic magical girl tropes and Japanese culture. These include a school festival where Punie terrorizes the crowd with her Miracle Rod, a midterm exam that turns into a violent cheating scheme under a sadistic substitute teacher, a sports festival that reenacts parodies of Japanese historical battles, and an amusement park date that Punie sabotages through extreme interference. Another arc sees Pyon and Potaru use a magic cupcake to become adults and launch another failed attack on their older sister. Through every episode, the story contrasts the cute, pastel aesthetic of magical girl manga with sudden, graphic violence and dark humor, all while Punie remains completely unapologetic about her brutal approach to solving problems.