In Imperial Calendar 2017, seven years have passed since the Holy Empire of Britannia occupied Japan. The Japanese people were deprived of their name and freedom, now called Elevens and their country as simply "Area 11."
After the war, Lelouch, a prince of Britannia, had been sent to Japan as a hostage. He currently hides his identity and lives as a student. When he is accidentally caught up in a fight between resistance members and the Britannian Force, he runs into a mysterious girl named C.C. and acquires the power to control anyone known as "Geass." With the power of Geass, he realises the time has come to bring down the Britannian Empire that had abandoned his sister Nunnally and himself. As a masked rebel named Zero, Lelouch leads the Black Knights, an anti-Britannian resistance group.
Meanwhile, his childhood friend, Suzaku Kururugi, is now part of the Britannian Force and a pilot of the new weapon Lancelot.
Two former friends are now on different sides, and their lives are about to be changed forever.