In the midst of WWII when food was scarce, the zookeepers of Ueno Zoo are given a devastating order to eliminate the wild animals in their care. They euthanize most animals except for three elephants whose thick skin protects them from the deadly needles. The elephants struggle to survive, and starve to death at the end. After the war ends, the children across the country plead for another elephant, leading Ueno Zoo to adopt Hanako, a young female elephant from Thailand. With proper training and loving care, Hanako quickly becomes the star of Ueno Zoo. Her life appears to be happy and peaceful until one day she is transferred to another zoo in Inogashira where she is kept in solitude.
Hanako was a real elephant and died on May 26, 2016 at the age of 69 and was the oldest elephant in Japan. She carried the title of "the loneliest elephant in the world" as she lived alone in a small fairly barren cement enclosure for 62 years at Inogashira zoo.