Hanabi Hyūga

is a member of the Hyuga Clan. She is the youngest daughter of Hiashi Hyuga, younger sister of Hinata Hyuga, and cousin of Neji Hyuga.

Background
Although Hanabi would normally, as the younger sibling, be put into one of the Hyuga clan's branch houses, her father felt that she has more talent than Hinata and thus has chosen to raise her as the heiress to the clan instead.

Part I
Hanabi watched Neji's match against Naruto during the final round of the Chunin Exams with her father, and was amazed to see that he had learned powerful secret techniques on his own. It was also indicated that she knew nothing about the failed attempt to kidnap Hinata that had resulted in Hizashi's death, mostly because she wasn't born at that time, as she did not know how her father could still be alive after the Land of Lightning demanded his death.

Hanabi appears four more times in the anime; when Kurenai Yuhi came to talk about having Hinata join Team 8, at the funeral of the Third Hokage, and at Tsunade's inauguration, standing with her cousin Neji and his teammate Tenten.

Part II
Although she has yet to make an appearance, Hanabi is noted to be away with her father during Pain's attack on Konoha.

Trivia

 * Hanabi's name means "fireworks".
 * She is a playable character in majority of the games in the Ultimate ninja series.