Claudia, the world of the sky, is dotted with floating islands in the sea of clouds.
Reinas, the captain of the Kaiserschult Empire's boat platoon, is ordered by the King to take control of Badelsen Island with his ally Ronald.
Reinas and Ronald launch a surprise attack on the island's key command tower. Reinas successfully conquered the command tower, but was dissatisfied with the military's way of slaughtering civilians and confronted Ronald. Reinas, guilty of treason, is chased by the Kaiserschult army.
An ever-increasing mysterious beast, suspicious rumors of King Kaiserschult, an entrance to a different space. Reinas' journey begins now, where various destinies intersect ...