In a future where "The World"—a mysterious location whose whereabouts are unknown—maintains global peace, making war a thing of the past, the airship Norn is assigned to carry nine people with special powers to this hidden place.
Boarding the ship are eight men and three women. Koharu, who has moved past her loneliness and resents her potentially destructive abilities, works with Mikoto Kuga, a noble who uses her barrier skills to protect the Norn and its passengers. Also present is Nanami Shiranui, whose power causes her personal suffering and drives her desire to end her life as atonement for past deeds. As the journey unfolds, tensions grow among the passengers due to an unexpected rise in the ship's headcount.
Their search for the stowaways is disrupted by a hostile attack aimed at stopping the Norn's progress at all costs. Amid this chaos, the passengers ponder the reasons behind their given abilities and their ultimate purpose upon reaching The World.
