 A continuation of the autobiographical story of Keiji Nakazawa as he grew up in Hiroshima in the aftermath of the atomic bombing. Having lost his father, sister and younger brother in the firestorm following the blast of the atomic bomb, Gen is struggling to take care of his mother and his baby sister, who was born on the day of the bombing. One day, Gen sees a young boy among a group of orphans who looks exactly like the brother he saw perish. Is there possibly a chance that he survived?