Who is Zuko's sister?

Zuko’s sister is Azula, the Fire Nation princess and daughter of Fire Lord Ozai. She is Zuko’s younger sister and the favored heir in their highly competitive royal family.

Azula is introduced as an exceptionally gifted firebender whose blue flames and lightning generation distinguish her from most other characters. Ozai praises her talent and discipline, while Zuko is treated as a disappointment after speaking out against the Fire Nation’s military leadership. This family imbalance drives much of the siblings’ conflict.

Ty Lee and Mai are Azula’s close friends and members of her elite team, but neither is related to Zuko. Katara is an ally of Aang and a member of the Southern Water Tribe, making her a major opponent of the Fire Nation rather than a member of Zuko’s family. Zuko and Azula’s relationship remains central to the series’ themes of power, abuse, rivalry, and redemption.