The Miyama-Uguisu Mansion Incident is a one-shot manga written by Katou Kazue that introduced the main concepts of Ao no Exorcist. Due to the positive reception it recived she began work on the latter.
* The main character was not Rin but a similar character named Night. He is demon similar to Blacky who has taken human form.
* The main villain is named Pazuzu, who shares some similarities to Satan.
* The secondary character, Monaka, is similar to Shiemi.
* Oribe who is possessed by Pazuzu, is similar to Shiro Fujimoto.