In the near future, fleeing the unending violence on earth, humans have regrouped to a mysterious platform known as CIEL, hovering over their erstwhile home. Out of the ranks of the endless wars rises Jean de Men, a charismatic and bloodthirsty cult leader who turns CIEL into a quasi-corporate police state. A group of rebels unite to dismantle his iron rule - galvanised by the heroic song of Joan, a child-warrior who possesses a mysterious force...