鲁路修本是帝国的王子，在母后遇害后，和失明的妹妹一起被流放到11区（原日本国）作为人质。在那里他们结识了日本王子朱雀，三人共同度过一段美好的童年时光。帝国最终全面攻陷了11区，鲁路修和妹妹的安宁生活再次被剥夺，朱雀和他们也分散了。 鲁路修和妹妹隐瞒身份，过着看似平凡的学生生活。然而鲁路修心中对于帝国的仇恨却未停止。他希望摧毁帝国，为妹妹营造一个可以快乐生活的世界。这一切随着神秘少女C.C的出现变得不再遥不可及。 此时朱雀也再次出现在他们的生活中，然而残酷的现实让童年的挚友难以重温童年往事。这里没有正义和邪恶，黑暗与光明，有的仅仅是艰难的抉择和难以预料的明天。The Empire of Britannia has invaded Japan using giant robot weapons called Knightmare Frames. Japan is now referred to as Area 11, and its people the 11's. A Britannian who was living in Japan at the time, Lelouch, vowed to his Japanese friend Suzaku that he'd destroy Britannia. Years later, Lelouch is in high school, but regularly skips out of school to go play chess and gamble on himself. One day, he stumbles on terrorists 11's who've stolen a military secret and is caught by a member of the Britannian task force sent after them, who is Suzaku. As the rest of the squad arrives, Suzaku is shot for disobeying orders, while the military secret, a young immortal witch, gives Lelouch the power of Geass, which makes anyone obey any order. While Suzaku is secretly made the pilot of Britannia's brand new prototype Knightmare, Lancelot, Lelouch becomes the masked Zero to lead the rebellion to destroy Britannia once and for all.
