Ryo is a boy broken on an emotional level, doesn't go to school anymore and locks himself inside at home. Hiroki is a student constantly talking about changing the world, but struggles to keep up with his friends. Ami, an isolated girl, comes into the life of both boys. The three of them get alienated from society and slowly, but surely, from each other and themselves.

Airi is a graduate student with a degree in the study of folklore. As part of her research, she decided to go to a small village with a group of friends, to investigate local legends. She does not know that the people worshiped the Slit-Mouthed woman as a living god, and intend to use her and her friends as a human sacrifice. In the end, Airi is injured and decides to fight, becoming a Slit-Mouth hunter.”