In 2700 AD civilization falls into chaos after a series of natural disasters re-shape the world. Countries and people are torn apart. Or, far worse, forced together. Society fractures.
Now it is 3000 AD. While humanity has survived and has the use of some technology, it's level and usage is uneven. With the help of the Cult of Saint Ruka, life goes on... except where members of "Madness" (a crazed group of individuals who enjoy causing murder and mayhem) wander through the area. Wherever "Madness" appears, death is left in their wake. Until three years ago when the leader of "Madness", Kyou, was supposedly killed.
Left for dead, Kyou lost his memory and was imprisoned in a cage beneath a Cult church. The local priest, Izaya, looks after Kyou, trying his best to instill kindness and compassion. Until the day that "Madness" arrives...