Kishin Houkou Demonbane
Alternate Title(s): 機神咆吼デモンベイン; Demonbane; Roar of the Machine God Demonbane
Official Website: (Japanese)
Genre(s): Comedy, Mecha, Romance, Science Fiction, Supernatural
Episodes: 12; 1 OAV
Opening Theme: "Hito, Kami, Hata - Man God Machine" - Yuichi Ikuzawa
Ending Theme: "Modern Rose" - Kanako Itou
Summary:  "Kuro Daijuuji is a poor detective living in Arkham City. One day, he was requested by Ruri Hado of Hado Financial Group, to search for a magic book. While he initially refused, Ruri offered him a large sum of money upon completion of her request, in which bribed Kuro to accept. As Kuro searches for the book, he unexpectedly runs into Al, a pretty girl that is actually a powerful grimoire. They forge a contract with each other, bestowing Kuro with powerful magic. Soon afterwards, Al also activates Demonbane, a deus machina owned by the Hado Financial Group, to combat the mechanical menace from the Black Lodge. With this, the war between the Hado Financial Group and the Black Lodge begins....."

~ANN, src