Kaguya Sumeragi

Kaguya Sumeragi (皇 神楽耶, Sumeragi Kaguya), 14 years old (15 at R2), is the young head mistress of the Kyōto House and a supporter of the Black Knights. She is also a close friend of Empress Tianzi of China. Despite her age and physique, she possesses a strong will and is highly influential amongst the Houses. Kaguya has admired Zero since his debut, and wishes to have his hand in marriage. Nothing anyone says contrary to this desire seems to faze her, including the suggestion that Zero might be sleeping with other women - formed from the idea that Kallen, C.C. and Zero had escaped capture and remained together in secret for a full year - to which she later decides that "A true hero enjoys physical pleasures," and proceeds to suggest that she, Kallen, and C.C. are Zero's harem.

Kaguya met Lelouch and Nunnally during their childhood at the Kururugi Shrine, and is Suzaku's cousin. A Sound Drama set in the second season reveals that she was engaged to Suzaku, and was cruel to him because he wouldn't allow her to play with him and his friends at the behest of Taizo Kirihara. Becoming frustrated when Suzaku again refuses to play with her and insists that she studies, she runs off into the nearby forest. There, she runs into Lelouch, who she mistakes for the "demon of the forest", and he permits the misunderstanding to continue. Fearful, she attempts to secure her safety by using the Sumeragi name to intimidate him, which is met with scorn, but he permits her to leave. At this she admits that she does not want to return, because they do not let her do the things she desires, but cannot be anything other than a Sumeragi. Lelouch insults her lack of ability, saying that none would desire such a woman, and that she has no merit. Crying, she flees and runs back to the shrine, and apologises to Suzaku, who comforts her and says that he'll ask his father if she can play with him. Several yeas later, she says that she believes that she's changed since then. When Zero suggests that he may be a demon, she says that is fine, because the important thing is that she chose him herself.

She appears during the first season during a Kyoto House meeting, hidden behind a screen, and properly introduces herself to Zero just before the Battle Of Tokyo. She offers to be Zero's wife, claiming that she is a goddess of victory, but is rebuffed, as he says that he sold his soul to a devil, and cannot be a goddess's friend.

She is the only living member of the Kyōto House following the Black Rebellion, having managed to escape to the Chinese Federation until Zero's return one year later. She is aboard the Black Knight's submarine when it reinforces Zero, pleased to meet him again. After the formation of the United Federation of Nations, she became the representative of the United States of Japan as well as the First Chairwoman of the U.F.N. Supreme Council. During the assault on Area 11, Kaguya is present on the Li Xingke's command transport. After receiving word of Zero's death and the armistice between the Black Knights and the Britannian forces, Kaguya returns to the Ikaruga to negotiate the armistice terms. Though she is deeply saddened by the news of Zero's death, she remain strong in her resolve and intends to utilize Zero's death as much as possible for the benefit of the U.F.N. She is present when news of a rebellion within the Emperor's forces near Kaminejima arrives. Believing that only one person could cause such chaos, Kaguya decides to follow Schneizel to the island. She also postpones their meeting, needing to confirm several details first. When Lelouch is crowned Emperor, Kaguya and the rest of the Black Knights are visibly stunned.

After Lelouch installs himself as Emperor the following month, she chairs Britannia's entrance into the U.F.N. She and the others easily see through the fact that Britannia's large population would give it a supermajority vote in the UFN, effectively giving Lelouch control of the organization, and try to get him to limit his vote. Lelouch instead takes her and everyone else present hostage to force the issue. She, along with the other hostages, are later released by Sayoko. Kaguya is later kidnapped by Lelouch, and she is slated for public execution along with Tianzi, Xingke, Ohgi, Kallen, Schneizel and others. They're all released when Lelouch is killed by Suzaku (dressed as Zero). She is last seen attending Viletta and Ohgi's wedding.

Abilities
Despite her age and physique, Kaguya reveals herself to be wise and skilled beyond her years, managing to score the second highest total attributes rating among the core members of the Black Knights, behind Tohdoh. Specifically, she is the most charismatic member of the Black Knights, second most loyal and matching Diethard for second most intelligent (behind Kallen and Rakshata, respectively.)

Trivia

 * Her poem in the Code Geass DVD reveals that she mourns Lelouch and wonders what would have happened if they had knew the true Lelouch earlier on.