Kaze Tachinu - - Hikoukigumo

The song was not originally written for the film. It was the debut single of (then Yumi Arai), released in 1973 when she was just a high school student.

Just like a vapor trail, Jiro’s "ten years in the sun" (his creative prime) and his time with Naoko are intensely beautiful but painfully short-lived. Kaze Tachinu - Hikoukigumo

The song plays into the film’s central question: how does an artist create something beautiful in a world that is broken? Jiro’s planes are masterpieces of engineering, but they are also tools of war. The song was not originally written for the film