Kal-el Albus, an exiled prince who lost his kingdom to revolution, sets out aboard the flying island Isla on a journey to the end of the sky with no promise of return. Sworn to revenge, he trains as a pilot alongside Claire Cruz, a fellow cadet he falls for without knowing she is the figurehead of the very revolution that toppled his family, and the two fly as a pair through increasingly hostile skies. This manga adapts the original light novel series.