According to Kadokawa's notice to the bookstores, Mikumo Gakuto's light novel "Dantalian no Shoka (Bibliotheca Mystica de Dantalian)" was announced to get an anime adaptation. The details will be revealed in The Sneaker magazine on June 30th.

Cover of the novel vol.2

Dantalian no Shoka has been serialized in The Sneaker magazine since August 2008 and its manga adaptations have been published in Monthly Shonen Ace and Monthly Comp Ace since March 2010.

Synopsis:
Hugh Anthony Disward inherits an old mansion and a personal library from his grandfather. In the basement of the mansion, he meets a mysterious girl Dalian. She is a Dantalian and a gateway to "Dantalian's bookshelf", which stores the prohibited books of the demons. "Gensho (Illusory Books)", the prohibited books, endanger the balance of the world but people are fascinated by the taboo. Huey and Dalian solve the cases involving Gensho with their ability to access to Dantalian's bookshelf.

Source: Scan of the notice