The year 20 atb. . Japan was striving for world domination superpower conquered by Britain and in "Area 11" renamed.
Seven years later, the British prince Lelouch Lamperouge, who was sent with his sister as a hostage to Japan, and now "incognito", leaves a strange encounter. He meets a girl with green hair, which is called CC and apparently immortal. It ends with her a contract. He must meet her one of her wishes, in return. He gets the power that everyone obeys his orders: the Geass.