In a world where the government dictates what people should and should not read, libraries have had to resort to creating an army, called the Library Defense Force to protect the collections they have from being confiscated by the dreaded military Media Betterment Act army.
Iku Kasahara has fulfilled her dream of being recruited by the LDF but the training is difficult. Not only does she physically have to be in shape, but she has to memorize the entire layout of the library and know where every book is located (this in itself is boring enough to make any student fall asleep).
There are many humourous side comments about her training and trainers, especially good-looking Sergeant Atsushi Dojo. Despite his being particularly hard on her, Dojo can be surprisingly gentle at times.