Tita Mu Koshigaya is a young woman who captains a ship, the Cha-Cha Maru, whose business is capturing exotic creatures in the 'sea of clouds' of the planet Ietta, and selling them to collectors and zoos. By chance, she saves Elysse Aldo Mordish, a young woman of her own age, from a rogue faction of Ietta's own military forces, led by the armored commander Guizel, who already killed Elysse's scientist father. As the military conducts a vicious chase for Elysse, it becomes apparent that she holds the key to a secret that could determine the fate of the entire planet's independence.