A catastrophic earthquake has left Tokyo, and most of the Earth for that matter, under the sea. Aika is a salvager who retrieves various remains from the watery ruins. When Aika accepts the dangerous mission of locating and obtaining the mysterious Lagu, she discovers that she's not the only one after it.

A deadly virus known as "Algernon" has attacked humanity with vicious meaning. At the forefront of the battle is the mystifying Akamatsu Industries—disguised as a heavy machine factory in Tokyo, this undercover organization uses neural enhanced weapons known as NeuroNoids to battle Algernon. Also helping with their secret efforts is the mysterious mutant who is only known as "Betterman." (Source: ANN)

In the year 2010, the Holy Empire of Britannia is establishing itself as a dominant military nation, starting with the conquest of Japan. Renamed to Area 11 after its swift defeat, Japan has seen significant resistance against these tyrants in an attempt to regain independence. Lelouch Lamperouge, a Britannian student, unfortunately finds himself caught in a crossfire between the Britannian and the Area 11 rebel armed forces. He is able to escape, however, thanks to the timely appearance of a mysterious girl named C.C., who bestows upon him Geass, the "Power of Kings." Realizing the vast potential of his newfound "power of absolute obedience," Lelouch embarks upon a perilous journey as the masked vigilante known as Zero, leading a merciless onslaught against Britannia in order to get revenge once and for all. [Written by MAL Rewrite]

One year has passed since the Black Rebellion, a failed uprising against the Holy Britannian Empire led by the masked vigilante Zero, who is now missing. At a loss without their revolutionary leader, Area 11's resistance group—the Black Knights—find themselves too powerless to combat the brutality inflicted upon the Elevens by Britannia, which has increased significantly in order to crush any hope of a future revolt. Lelouch Lamperouge, having lost all memory of his double life, is living peacefully alongside his friends as a high school student at Ashford Academy. His former partner C.C., unable to accept this turn of events, takes it upon herself to remind him of his past purpose, hoping that the mastermind Zero will rise once again to finish what he started, in this thrilling conclusion to the series. [Written by MAL Rewrite]