The story is set in a world where Devils are born from human fears. Devils are usually dangerous and malevolent, their power proportional to the fear they incite. However, humans can form contracts with them to use their power, and there are individuals specializing in hunting and employing them, called Devil hunters. Devils originate from Hell, and exist in a cycle between Earth and Hell: they migrate to Earth when killed in Hell, and vice-versa. Dwelling in Hell are extremely powerful Devils called Primal Fears, which have never been killed. Transit between planes appears to be overseen by the Hell Devil.
死体が喋っている
