Demonbane

Original : Kishin Houkou Demonbane (2006)
Japanese : 機 神 咆吼 デモンベイン
English : Demonbane
Genre : Action Comedy
Tags : Ecchi, industrialization, Magic, Mecha, Romance, Super Robots
Manga
Written by : Takashi Tanegashima
Published by : Kadokawa Shoten
Original run : 2004 – 2006
Volumes : 4
Anime
Directed by : Shoichi Masuo
Original run : May 18, 2006 – August 17, 2006
Episodes : 12

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....