From a young age, Kurumi Mirai has aspired to become a magician. Driven by her ambition, she has spent her childhood preparing to join the prestigious Rettoran Academy of Magic. Although Kurumi excels in the selection exam, her dream is crushed when she is not chosen for the elite magic class. Admitted to the standard class at the academy instead, Kurumi soon befriends Maki Kumiiru, her new roommate; and Yuzu Edel, another girl unhappy with her placement. However, to everyone's surprise, their homeroom teacher, Minami Suzuki, promises to teach the class magic anyway. Although skeptical at first, the girls start to believe that this may be their second chance at realizing their dreams and becoming wonderful magicians.

In 1973, following the ruthless six-year-long Lunar War, the hostile alien species known as the BETA—Beings of Extra Terrestrial origin which are Adversary of the human race—invaded Earth, killing billions and decimating Eurasia. While BETA can be destroyed with conventional weapons, their laser-class is able to wipe out entire aircraft fleets, forcing mankind to develop giant combat suits called Tactical Surface Fighters (TSF) to combat them. When the BETA reach Japan in 1998, military school student and TSF pilot—or eishi—Yui Takamura is ordered to defend Kyoto's last line of defense with her fellow classmates. At the cost of countless human lives and the sacrifice of Yui's friends, the Japanese Imperial Army manages to repel the invaders, leaving destruction in its wake. However, this encounter leaves Yui determined to never again allow something like this to occur. Three years later, now a lieutenant, Yui joins the XFJ project, an Alaska-based Japan-American TSF development program. In an international team composed of the uncooperative Japanese-American test pilot Yuuya Bridges and various eishi from countries lost to the BETA, Yui's task is to help develop the new Japanese TSF Shiranui. Amidst political tensions inherited from the Cold War, Muv-Luv Alternative: Total Eclipse follows Yui's delicate mission and Yuuya's journey to overcome the demons of the past that still haunt him.

Sakura Nankyoku is a total otaku. Due to a fluke, she gets elected as her class' Student Council President. Everything takes off from there into a series of crazy misadventures revolving around Sakura, her family, and her classmates. (Source: ANN)

The Labyrinth is an expansive space deep underground where humans live in clusters known as colonies. Over the years, the surface has become a distant memory—even perhaps only a fantasy to those who have never experienced its wonders. Making sure humanity survives the harsh conditions of the underground, a colony's citizens can take on a variety of specialized jobs. These include Workers, who mine precious ore to fuel the colonies, and Markers, who journey into the Labyrinth's surprisingly lush environment to bring back information that eases navigation. However, humanity also faces a threat to its existence—creatures called kaijuu whose sizes range from that of a small child to an enormous building, and are hostile to any human they see. Moreover, kaijuu that are large enough can force their way into the colonies, further increasing their threat level. Memenpu is a nine-year-old college graduate whose inventions have greatly benefitted the Workers in her local colony. Recently, however, she has been dreaming of a place with a neverending ceiling not bound by bedrock. These aspirations fuel her desire to become a Marker and explore the Labyrinth's vast unknown in search of such a fantastical place. Despite her father Gagumber's vehement disagreement, a certain incident with the kaijuu jumpstarts a dangerous yet exciting adventure that will surely alter humanity's course forever.