The discovery of a hypergate on the Moon once allowed the human race to teleport to Mars. Those who chose to settle there unearthed a technology far more advanced than that of their home planet, which they named "Aldnoah." This discovery led to the founding of the Vers Empire of Mars and a declaration of war against the "Terrans," those who stayed behind on Earth. However, a battle on the moon—later called "Heaven's Fall"—caused the hypergate to explode, destroying the moon and leading the two planets to establish an uneasy ceasefire. Their peace was a fragile one, however. Fifteen years later, high school student Inaho Kaizuka witnesses the plotted assassination of the Vers Empire's Princess Asseylum Vers Allusia, who had come to Earth in hopes of repairing the relationship between the empire and its homeland. The ceasefire is shattered, and the Martians declare war on the Terrans once again. In the face of this insurmountable enemy, Inaho and his friends must now fight against the Vers Empire to settle the war once and for all. [Written by MAL Rewrite]

Thirteen girls, each with the ability to materialize "Elements" and summon metallic guardians called "Childs" have been brought to Fuuka Academy to battle mysterious creatures called Orphans. Each with a different personality and background, they must decide who they truly care about and why they fight.

Hikaru Shidou, Umi Ryuuzaki, and Fuu Hououji are strangers brought together by fate when they meet during a seemingly normal field trip to Tokyo Tower. Accompanied by a great flash of light, they hear a mysterious woman's plea to save "Cephiro," and the junior high heroines are suddenly swept away by a giant flying fish. Afterwards, they arrive in an unknown land, where they encounter a man called Master Mage Clef. Clef informs the girls that they were summoned by Princess Emeraude to fulfill their destinies as Magic Knights, restoring peace and balance in Cephiro. The formerly lively and peaceful land has been in disarray ever since High Priest Zagato imprisoned the princess, who acted as Cephiro's pillar of stability. The Magic Knights reluctantly accept Clef's words as truth and embark on a journey to save Cephiro from the clutches of evil. [Written by MAL Rewrite]

Unlike many schools, attending Hyakkaou Private Academy prepares students for their time in the real world. Since many of the students are the children of the richest people in the world, the academy has its quirks that separate it from all the others. By day, it is a normal school, educating its pupils in history, languages, and the like. But at night, it turns into a gambling den, educating them in the art of dealing with money and manipulating people. Money is power; those who come out on top in the games stand at the top of the school. Yumeko Jabami, a seemingly naive and beautiful transfer student, is ready to try her hand at Hyakkaou's special curriculum. Unlike the rest, she doesn't play to win, but for the thrill of the gamble, and her borderline insane way of gambling might just bring too many new cards to the table. [Written by MAL Rewrite]