To really enjoy this series, there are two hurdles that must be passed:
1. Disbelief of the fact that these people are fighting to the death over books
2. The extremely dull and lifeless opening
With that small disclaimer aside, Toshokan Sensou is an anime series that follows the beaten path in many regards, but does it so well that the lack of originality can be forgiven. Nothing is done here that hasn't been done before, and not every single element works, but it's certainly satisfactory as a brisk watch. Some series try to wow with deep drama, complex plots, and dizzying relationship webs. Others opt for the simpler route of entertaining action, linear plots, and a few interesting characters mixed with good humor to spice things up. Toshokan Sensou borrows a lot from the second category.
The synopsis is simple enough, while still being somewhat fascinatingt: In the not so distant future, the Japanese government has crippled the people's right to freedom of speech to prevent the spread of misinformation. To aid them in this unpopular task, the Media Enhancement Committee has been founded and enforces the government's ruling with little mercy.
However, at the same time, the libraries were given the right to be militarized bastions of knowledge, where people can read whatever they want whenever they like. The libraries are tasked with keeping books away from the Media Enhancement Committee, sometimes resulting in open warfare between the two factions. It's a curiously dystopian setting, but it never feels hopeless or deprived, which is both a strength and a weakness for the series.
And this is where Iku Kasahara, the main character, enters. The story follows her rise through the ranks of the Library Task Force and her increasingly tense relationship with her commanding officer, Lieutenant Dojo... all the while keeping it a secret from her protective and conservative parents.
The characters, again nothing unique, are nonetheless well rounded and diverse enough to hold interest. Kasahara does well showing the burden of being the first female in the Task Force, as well as being in the Task Force in general. While she may be annoying at times with her overreactions, she's nonetheless realistic enough to let that slide.
The others do well enough at sticking to their post, some even standing out long after the series is over, the GAR captain being a notable example.
Animation and music are, unfortunately, nothing worth writing home about. It's all very solid, and I had no complaints, but nothing was done well enough to warrant much of a mention.
While the character interactions are satisfactory and occasionally compelling, the combat lacks some of that spark due to the very Capture the Flag-ish feel to it. It's engrossing to a degree, right up until you remember that they're fighting over books, and only for that purpose. There's no true animosity between the Media Enhancement Committee and the Library Task Force, it's all just part of the job for both. The constant shifting between the conflict and Kasahara's personal life can be jarring at times.
While a little character development is good for a primarily action series, it feels awkward and rushed in some places, obviously to cram as much of the material in the light novels in as possible. This is further sadly enforced by a small glimpse into the inner workings of the Media Enhancement Committee, which doesn't completely fulfill its intention of making them look slightly more sympathetic as punch clock villains.
Again, Toshokan Sensou is a series where people are willing to fight to the death for books. If this premise seems too ridiculous for you, you might not take the well executed combat or plot devices seriously, and thus will cease to enjoy this. Other than that, there's hardly any objectionable content. Good guys win, bad guys lose, characters develop with a little comedy thrown in, dystopian doesn't necessarily equal horrible conditions... nothing that will offend.
I certainly recommend Toshokan Sensou. It may not be perfect or particularly original, but it succeeds very well. If it had a little more focus and a slightly less silly premise, it would be a truly excellent series. A second series would've definitely been beneficial for it. So while it isn't groundbreaking, it does what it does well... if a little schizophrenically.
I enjoyed it, and I see no reason why anybody who can get past the fact that they're fighting over books wouldn't. Pretty fun for such a short little series.