Five centuries hence, Shinichi Kakimoto is on a school excursion to Nara, the ancient Japanese capital, which is now depicted through an AI simulation of Himiko, Japan's first recorded ruler. Amid the scramble to evade the ravenous deer, Shinichi becomes separated from his classmates and encounters Toto, an odd girl who asserts she has never ventured outdoors. As the pair wander through the city, they form a connection that faces a trial when hostile pursuers begin hunting Toto.