Toaru Hikuushi e no Koiuta unfolds in a world where ancient mythology speaks of an "end of the sky" hidden beyond the clouds. Sent to Isla, a great island that travels through the air toward that unknown frontier, Kal-el Albus enters Cadoques High's Aerial Division and tries to live like an ordinary student. Behind that quiet routine is the past of Carl La Hire, a prince who has lost everything and carries anger, grief, and a desire for revenge into the voyage. At school he shares classes, training, and a once-carefree daily life with classmates such as Claire Cruz, Ariel Albus, and Ignacio Axis.
That calm does not last. A surprise attack by the Air Tribe throws Isla into a bloody war and turns its expedition into a fight for survival. As the battles in the sky grow fiercer, Kal-el and his schoolmates are forced to confront the hatred that divides nations as well as the bonds forming among them. Romance, aerial combat, and coming-of-age drama meet in a story about young pilots crossing the heavens in search of the world's farthest edge.