An anime about the real story of 15 year old Kayoko Hayashi. After the Nagasaki atomic bomb, Kayoko's body was found 21 days later crushed under the Shiroyama school building where she had been volunteering for the war effort. 50 cherry tree saplings were donated by her mother (6 of which have survived today) to the Shiroyama elementary school as a memorial to her daughter and to the other children who lost their lives so that people many pray for peace.