In the summber of 1945, Katsuo Hashimoto applies for the special attack corps. Overhearing a rumor that an attack would be ordered soon, Katsuo feigns illness, causing his friend Toshio to unexpectedly take his place. Katsuo is left with the words, 'Please, take care of my sister,' as Toshio disappears into the summer sky. 60 year later, Japan has long since lost the war. Katsuo, who has been struggling with his for many decades is diagnosed with pancreas cancer, and given a year and a half to live. Accepting his imminent death, he travels to the Reiryu Mountains in Tendou City, Yamagata, where Toshio's family temple is located to atone for his mistake.