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.
She likened her friend’s short life to a "vapor trail"—a white line in the sky that is brilliant for a moment before disappearing. Kaze Tachinu - Hikoukigumo
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. The song plays into the film’s central question: