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 girl, 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.
It's been one year since the failure of the Black Rebellion and the supposed death of Zero. Britannia has assigned Area 11 a "correctional education" status, where Elevens are made an example of by brute force, to try to prevent any future uprisings and suppress rebellious thoughts. Unsuspecting high school student Lelouch, oblivious to his rebellious past as Zero, stumbles upon a scheme on his life and the life of a mysterious woman known as C.C., who reveals to him his forgotten purpose and his "true" self. Destroying his assailants and declaring himself Zero once again, Lelouch sets out to finish what he started.
In Tokyo, an impenetrable field known as "Hell's Gate" appeared ten years ago. At the same time, psychics who wield paranormal powers at the cost of their conscience also emerged. Hei is one of the most powerful of these psychic agents, and along with his blind associate, Yin, works for one of the many rival agencies vying to unlock the mysteries of Hell's Gate.
Gene Starwind and his partner Jim Hawking run a small business on the backwater planet of Sentinel III. But all that changes the day that Hilda hires them for a bodyguard job. Now, thrust into a mystery they don't fully understand, they're on the run from the cops, the pirates, an angry alien, and a mysterious assassin. But they've got one thing going in their favor—they have the galaxy's most advanced ship, the Outlaw Star.
Lain Iwakura appears to be an ordinary girl, with almost no experience with computers. Yet the sudden suicide of a schoolmate, and a number of strange occurrences, conspire to pull Lain into the world of the Wired, where she gradually learns that nothing is what it seems to be... not even Lain herself.
Set in the Shinigami technical school for weapon meisters, the series revolves around 3 groups of each a weapon meister and a human weapon. Trying to make the latter a "Death Scythe" and thus fit for use by the Shinigami, they must collect the souls of 99 evil humans and 1 witch.