Hiroshima, summer of 1945. A young girl named Nobuko rescues a starving kitten from crows. Although her parents initially dismiss the idea of keeping the cat, she eventually persuades them to allow her to keep it. She and her brother Makoto give the kitten the name Kuro, and the animal quickly brings joy and laughter into the family. As World War II continues to take its toll on Japan, caring for Kuro becomes increasingly difficult. One August morning, the cat begins acting strangely.