Hades is a dark place stricken by a painful, environmental condition called Ashen Rain. The inhabitants of this world are stricken with fear the moment the skies darken. Claude, a young alchemist, braves the dangerous rain to find a cure for his ailing sister, Yuri. Cursed with a glowing Butterfly on her neck, Yuri struggles to maintain her strength while consuming the only thing capable of subduing her pain - a medicine that contains a rare ingredient called ‘snowdrops’.
As they arrive in a small town, Claude and Yuri are approached by a guard after he hears of strangers acting suspicious. After a skirmish with the local guards, Claude and his sister encounter an old man named Phineas. The plot quickly deepens when they discover that the old man is actually the leader of a sadistic cult. To make matters worse, Phineas discovers Yuri’s butterfly mark and believes she is a goddess sent to lead his people. Things couldn’t get any worse.