A story of a girl who suddenly woke up from an unknown place. As she wandered there, she accidentally met a boy who is somewhat a killing maniac. The girl is waiting for her salvation, she wanted to die. She don't know who is she and where did she came from, all that's left on her was a sling bag. She wanted to die peacefully and sinless. So the two swore to each other. The boy desperately wants to get out from that damned place, so he wanted the help of the girl and in exchange, the girl's wish will be granted, the boy will kill her if they successfully get out from there. But as they continue to find the exit, they encounter some residents that also dwells in there. The other residents try to hinder them. But the two didn't want to break their promise, so to fulfill their promise they fight and survive. What awaits to the two outside? What will happen to them? Will they achieved what they desire? Or will it only turn out into despair? (This story was inspired by: Satsuriku no Tenshi or Angels of Death in English)