In a world similar to our early 20th century, airships are the major mean of transportation. A group of aerial bandits, know as "Zarathustra," raids airships with fascinating skills and has angered and been feared by government forces. Yet, their target is not money or treasure: in the name of peace, they locate and destroy arms sales shipped by airships.

Kumo no Graduale was published in French by Soleil Manga from September 1, 2005, to May 24, 2006.