In a world dominated by the Holy Empire of Britannia, most of the globe has been conquered and forced into submission by this behemoth of a superpower. Japan, now renamed Area 11 after its defeat at the hands of the Empire, continues to harbour pockets of seemingly futile resistance that seems powerless in the face of the might before them.
Enter Lelouch Lamperouge, an exiled Britannian prince hidden away under a false name in Area 11 - harbouring a deep hatred for the empire which has forsaken him, he grabs the chance to fight back when a mysterious power known as "Geass" is bestowed upon him, and begins working from the shadows to bring Britannia to its knees as the faceless leader of Area 11's resistance.
In the distant technological future, civilization has reached its ultimate Net-based form. An "infection" in the past caused the automated systems to spiral out of order, resulting in a multi-leveled city structure that replicates itself infinitely in all directions. Now humanity has lost access to the city's controls, and is hunted down and purged by the defense system known as the Safeguard. In a tiny corner of the city, a little enclave known as the Electro-Fishers is facing eventual extinction, trapped between the threat of the Safeguard and dwindling food supplies. A girl named Zuru goes on a journey to find food for her village, only to inadvertently cause doom when an observation tower senses her and summons a Safeguard pack to eliminate the threat. With her companions dead and all escape routes blocked, the only thing that can save her now is the sudden arrival of Kiri the Wanderer, on his quest for the Net Terminal Genes, the key to restoring order to the world.
It is the second year of the Kowa Period. The world has unified around the reorganize United Federation of Nations, and has enjoyed days of continuing peace, but now, that peace suddenly comes to an end. Suzaku, while travelling as the masked man "Zero" accompanying Nunnally on her visit to the refugee camp, is defeated by a mysterious Knightmare Frame, and the two of them are taken away. Following secret orders from Schneizel, Kallen, Lloyd and Sayoko infiltrate Zilkistan, the Land of Warriors, where they are attacked by a mysterious Geass user. There in Zilkhstan is a person named CC., known to the assailants as the "former master". In the indomitable kingdom which once conquered even the great army of the Holy Britannian Empire, what do the people desire? Hope, or despair? The people of Zilkhstan Palace certainly know of Geass. What are they, and C.C., planning.
"Mine has been a life of much shame." Tokyo, 2036 (Showa year 111): a revolution in medical treatment has conquered death... By means of internal nanomachines and the "SH.E.L.L." system whose network controls them, human beings suffer no diseases, require no treatment for injuries, and are guaranteed a 120-year lifespan, free from illness. Yet this consummate social system warps the Japanese nation in a host of ways: unresolved economic disparities, ethical decadence resulting from deathlessness, grave environmental pollution, and the "Human Lost" phenomenon, in which people themselves, disconnected from the S.H.E.L.L. network, become malformed. Japan teeters wildly between two potential futures: civilization's restoration or its destruction. Atmospheric pollution suffuses "Route 16" in the Outside-the area outside the Route 16 beltway. Youzou Oba, who lives an idle, drug-saturated life, joins Masao Horiki, a mysterious man who associates with the drag-racing gangs, on an incursion.
Tanjiro Kamado, joined with Inosuke Hashibira, a boy raised by boars who wears a boar's head, and Zenitsu Agatsuma, a scared boy who reveals his true power when he sleeps, board the Infinity Train on a new mission with the Flame Pillar, Kyojuro Rengoku, to defeat a demon who has been tormenting the people and killing the demon slayers who oppose it.