Long ago, a mysterious shrine maiden sealed nature spirits inside forest trees to prevent them from terrorizing the world. Now, her descendant, a cheerful young princess named Suzu, is forbidden from leaving the palace. However, one day, after sneaking out into an area known as the "forbidden zone," Suzu finds a strange seed that grows into a fun-loving nature spirit. With her new friend, Suzu is eager to explore the outside world she has been kept from, despite not knowing the dangers of the forbidden zone—or why the seed was being kept there.