The Kingdom of Knights, Grandshelt. Its people lived peaceful lives, blessed by the power of crystals. Rain, commander of the airship squadron, receives a royal decree—investigate the Earth Shrine, where the magical barrier protecting it has waned, and determine the cause together with Lasswell, his childhood friend and deputy commander. Upon reaching the innermost chamber of the shrine, the two encounter a mysterious man clad in black armor. Overwhelmed by his immense power, Rain and Lasswell are defeated, and the Earth Crystal is shattered before their eyes. Though Rain and Lasswell narrowly survive, their airship is wrecked, and their comrades have fallen… And so, their quest began…