In the year 1989, the Japanese government passed the Media Betterment Act, allowing a group of soldiers known as the Media Betterment Committee (MBC) to destroy and censor any problematic media under the guise of protecting public morals. As a response, regional governments established the Library Defense Force (LDF), whose members take up arms and put their lives on the line to protect freedom of expression. At the top of the Kanto branch of the LDF stands the Library Task Force (LTF): an elite squad consisting of only the most exceptional fighters. As a high schooler, Iku Kasahara experienced the terror of censorship first-hand when she refused to surrender the newest volume of her favorite series to MBC agents. She only came out unscathed thanks to a lone member of the LDF, who protected her and her beloved book. Now in her 20s and still unable to forget the man who saved her, Kasahara joins the LDF in the hope of becoming just like her prince. But LDF training turns out to be far more rigorous than she could have imagined, and her instructor, LTF member Atsushi Doujou, seems fixated on making her life a living hell. Given her struggles, Kasahara is shocked when she is selected as one of the two new LTF recruits as a result of Doujou's recommendation. As Kasahara does all she can to become worthy of the LTF and unravel her enigmatic superior's motivations, she wages war—both on the battlefield and in her personal life.

Following a terror attack in which a helicopter crashed into a nuclear power plant, the Japanese government passes a law expanding the powers of the Media Betterment Committee (MBC). Knowing that the MBC will target author Kurato Touma due to the similarities between one of his novels and the terrorists' actions, journalist Maki Orikuchi asks the Library Defense Force (LDF) to act as his bodyguards. Meanwhile, the higher-ups of the LDF prepare to indict the MBC on the grounds that parts of its new authority are unconstitutional. With the very existence of the Media Betterment Act coming under scrutiny, the members of the Library Task Force must navigate both their blossoming relationships and the precarious political situation they find themselves in.

In the near future, humanity has taken its first steps towards journeying into the far reaches of the galaxy. Upon doing so they discover a huge race of insectoid aliens known as Space Monsters. These aliens seem dedicated to the eradication of mankind as they near closer and closer to discovering Earth. In response, humanity develops giant fighting robots piloted by hand-picked youth from around the world. Shortly after the discovery of the aliens, Noriko Takaya, the daughter of a famous deceased space captain, enters a training school despite her questionable talents as a pilot. There, she meets her polar opposite, the beautiful and talented Kazumi Amano, and is unexpectedly made to work together with her as they attempt to overcome the trauma of war as well as their own emotions.

On November 23, 1957, the whole world witnessed the Federal Republic of Zirnitra's monumental achievement of sending the first live animal—a dog—to outer space. Since then, the space race between the confederacy and its competitor, the United Kingdom of Arnack, has intensified; the two countries hope to one day send humans to the cosmos above. As a dog's biology is inherently different from a human's anatomy, there is no way to perfectly identify the risks involving space travel and its effects on an individual's body without actually sending someone for observation. However, Zirnitra's government has a potential solution: to experiment on vampires, whose biological similarity to humans is too significant to ignore. Despite being forcibly taken from her home in the mountains, vampire Irina Luminesk shows no resistance and is even willing to train as a test subject. Lev Leps, a former top candidate to become the first human cosmonaut, is designated to accompany Irina and act as her guide. Through their time together, Irina and Lev begin to develop a mutual love for outer space, bringing them closer together.