Kaguya Sumeragi

Kaguya is shown having a great sense of responsibility and generosity, showing great care and loyalty towards her subjects and allies, along with being such a noble figure among the Houses, allowing her to obtain such high influential around her. Even C.C., as cold as she was, acknowledged Kaguya as being genuinely kind. Kaguya is also very familiar within the Leadership of The Black Knights, mostly due to her admiration for Zero since his debut. Kaguya has wished to have his hand in marriage. Nothing anyone says contrary to this desire seems to faze her, including the suggestion that Zero might be having relationships with other women - formed from the idea that Kallen Kōzuki, 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. However, this is merely a façade of a young maiden's beliefs and dreams regarding the power of dignity. Being born into a high-status family, Kaguya had been spoiled by her authority figures during her childhood, until an incident involving Lelouch vi Britannia inspires her about the nature of desires and arrogance. Therefore, Kaguya has constantly fantasized that anything is justified as long as people pursue peace, in turn creating a proper cycle and unlimited opportunities for humanity, including herself. This personality flaw has been heavily remarked by Lelouch, eventually resulting her overwhelming downfall against the tyrannous actions from "The Treacherous Emperor".

Kaguya has black hair (her hair is kept in two ponytails during the first season) and green eyes. She wears a pink-ish blouse that has detached sleeves along with a red miniskirt. In the second season, she often wears a long pink dress with red details.

Despite her age and physique, Kaguya is wise and skilled beyond her years, managing to score the second highest total attributes rating among the core members of the Black Knights, behind Kyoshiro Tohdoh. Specifically, she is the most charismatic member of the Black Knights, second most loyal and second for most intelligence matching Diethard Ried and behind Rakshata Chawla.