Lelouch Lamperouge, a Britannian student, accidentally gets involved with a group of terrorists. He meets a mysterious woman who gives him the powers of Geass, the "Power of Kings".
While Lelouch comes to realize his new power, using it and his superior strategic abilities to help the terrorists in their attack. The White Knight arrives, and ruins his plans.
Lelouch is reunited with C2, the strange girl who granted him the power of Geass. Since Zero confessed to Clovis' murder, Suzaku is acquitted of all charges. He meets Princess Euphemia, who has him guide her around Area 11.
Suzaku is enrolled in Ashford Academy, but is shunned because of his association in the murder of the previous Viceroy. Although he and Lelouch are old friends, they decide to keep it a secret for Lelouch's sake.
Zero's Black Knights are becoming a rallying point for Japanese, and they receive "gifts" from the main underground Japanese forces. Zero once again inserts his forces into battle, with the intention of capturing Cornelia.
Zero manages to destroy most of Cornelia's units and the superior technology of Kallen's Knighmare is enough to take on the White Knight, who saves Cornelia. Lelouch is pursued by the White Knight.
Shirly plucks up the courage to ask Lelouch out. Lelouch assumes the identity of Zero and goes to meet the main figures in the Japanese rebellion, wanting to gain their support.
Lelouch has doubts about his actions, as they caused the death of Shirly's father. Viletta reveals to Shirly that she believes that Lelouch is involved with the Black Knights, those responsible for her father's death.
Lelouch is scattered as he can not remember what happened when he was unconscious. Shirly found out that he is Zero. Mao reveals his presence. He also has the power of Geass.
An inauguration ceremony is held for Clovis' memorial art museum, with Euphemia judging the art contest. Lelouch helps Kyoshiro Tohdoh's comrades rescue their leader.
Lelouch now knows the identity of the White Knight as his friend, Suzaku, who is officially named Princess Euphemia's Knight. Lelouch draws Suzaku into a trap.
Lelouch, Euphemia, Suzaku and Kallen find themselves on a mysterious Island. Euphemia knows that Zero's true identity, Lelouch, is her brother. Suzaku finds out that Kallen is the pilot of Guren.
Lelouch must decide whether to accept Euphy's terms of peace. His motives for destroying Britannia is to create a peaceful world for his sister Nunnally, but he also recognizes his want for revenge.
Lelouch's accidental Geass on Euphemia destroys any hope of peace, and Suzaku, enraged at what Zero has done, sets out with revenge in mind. V2 reveals Zero's secret of Geass to Suzaku.
After using his Geass on Cornelia, Lelouch discovers that she doesn't know who killed his mother. C2 senses that Nunnally has been kidnapped, and Lelouch abandons the Black Knights to rescue her.
