In the winter of 1945, Sakura the elephant gave birth to a baby elephant at Tokyo Fujimi Zoo under the watchful eye of the zookeeper Shota Tanabe. Around the same time, Shota's wife, Setsuko, also gave birth to a son. Hanako, the baby elephant, grows up while deepening her bonds with elementary school students who love zoos. However, as Japan enters the Pacific War, the military orders the animals in the zoos of five major cities to be killed.