Jirou dreams of flying and designing beautiful airplanes, inspired by the famous Italian aeronautical designer Caproni. Nearsighted from a young age and thus unable to become a pilot, Jirou joins the aircraft division of a major Japanese engineering company in 1927. His genius is soon recognized, and he grows to become one of the world's most accomplished airplane designers.

Key historical events deeply affected the course of Jirou's life, including the great Kanto earthquake of 1923, the Great Depression, the tuberculosis epidemic, and Japan's plunge into war. He meets and falls in love with Naoko, grows and cherishes his friendship with his colleague Honjou, and innovates tremendously, leading the aviation world into the future.