While this movie does explain the major plot points of the anime series and features a standalone story that can be enjoyed by anyone, it is still a direct sequel. You'll get the most out of this movie if you're familiar with the characters and their relationships with each other.
So how does this compare with the original anime series? The feel is more or less the same, though it's great to see the story play out with Production I.G.'s top-notch animation. Some scenes, particularly the chase scene and the climax, stand out quite well because of the dynamic sense of movement and detail in the backgrounds, and the romantic moments are portrayed with great use of lighting and atmosphere.
The plot, too, is what you would expect from the Library Wars setting. Our heroes Iku and Dojo are charged with protecting an elderly writer from the heinous clutches of the Media Betterment Committee. The story is well-paced from start to finish and moves along briskly, not even dragging in the middle part where the action is slow.
It's interesting how at one point in the movie Iku admits to being more interested in characters and forgetting the overall plot whenever she reads books - this is precisely how I feel about Library Wars as a whole. The setting is still ridiculous and the villains are never really given an identity or a proper motivation, but the characters are so down-to-earth and charming that it is hard to focus on the flaws. Library Wars treats its unbelievable setting with seriousness and dignity, but it is hard to believe the characters are ever in any real danger even as the bullets fly. Even so, it's so easy to root for the characters and to cheer for Iku when she displays her boundless courage. To be able to pull this off without much serious dramatic tension takes some great writing.
The movie will probably best appeal to romance fans who enjoy a bit of action here and there. Picking up directly where the series left off, Iku and Dojo's newly discovered intimacy lies at the very heart of the story. It inspires Iku in particular to be braver, and the influence is always felt while never feeling overstated. It is not a particularly deep love story but it works in this movie in particular because of how grounded the interactions are in the characters and their idiosyncrasies.
Library Wars is an underappreciated gem of a series and it is a shame the movie has not seemed to have gotten the exposure it deserves. While the setting might not get the closure it deserves by the end, the characters certainly do. It's definitely worth your time to check out, both for newcomers and veterans to the franchise. It's easy to watch and the characters are fun. There's really not that much more we can ask for in a story.
