A disabled girl who lives in a lunar civilization after the Eugenic War slips away from her class field trip when she spots a secret passageway in the castle they are exploring.

Almost a hundred years ago, people built a road at the cost of destroying a local lake. A young boy sets out deliver vengeance and justice for the wronged party, but in doing so, finds himself dealing with a problem he couldn't have imagined: the war between the roads and the water.