In the mountains of Joseon, Jeongsoon has a heart as gentle as jade, but she might just be the clumsiest girl in the kingdom. She wants to be a princess, so she enters the grand princess challenge where she must complete the Manners Test, the Wisdom Test, and finally—the Sleep Test. Upon laying down on dozens of mattresses, Jeongsoon hears the squeaking of a hungry mouse (who close readers will have spotted hiding in previous spreads) and helps it to the palace kitchens for a midnight snack. Throughout each examination, Jeongsoon is far from flawless but in staying true to herself, wins the favour of the queen and the competition itself. Backmatter includes information about the real-life Korean princesses of the Joseon period, glossary, and author's note.