This anime follows Iku and her fellow soldiers as they protect various special books and artifacts from the oppression of the Media Enhancement Law Commission.
In the near future in Japan, the Media Enhancement Law has been forced upon the population censoring all books and media.
The folks at Discotek Media have found some additional distribution for one of their catalog series with the 2015 pickup of the Library War series.
The show aired in the spring of 2008 and produced an OVA and a movie after that.