Hyūga Clan

The is one of the oldest and most powerful clans in Konohagakure. All members born into this family possess the Byakugan, a kekkei genkai that gives them extended fields of vision and the ability to see the chakra circulatory system amongst other things.

Background
The clan is separated into two parts, the and the, a system that protects the secrets of the Byakugan from outsiders. The main house runs the family while the branch house protects it. The members of the branch house are branded with a cursed seal upon the next heir/heiress of the main house's third birthday. This seal gives the main house members absolute control over the branch members, because they can destroy the branch members' minds with a simple hand gesture, or cause them great pain to punish them. This seal also makes sure the secret of the Hyūga's Byakugan is safe, because it seals the Byakugan after the wearer of the seal dies. Because they are essentially servants, simply because of their birth order or heritage, some branch house members are hostile to those of the main house.

Abilities
Members of the clan are instructed in the use of the Gentle Fist style, which uses the Byakugan to view the opponent's Chakra Pathway System and deal precise blows to disable and impede the flow of chakra. Due to training in this style, Hyūga clan members tend to have excellent chakra control. This is emphasized in jutsu that utilize this chakra control, as well as the nuances of the Gentle Fist style. The clan's strongest techniques, like the Eight Trigrams Sixty-Four Palms, are only allowed to be taught to members of the main house. Neji Hyūga, however, has bypassed this restriction by learning them on his own, earning a reputation as a "genius" in the clan.

Other Clan Members
Throughout the series there have been several unnamed clan members that have played minor roles worth noting.
 * One member was shown during the initial part of Pain's invasion, he was a member of Konoha's barrier squad.
 * Another member was shown during the same invasion alongside Sakura. He uses his Byakugan to inform her of the development of the battle between Pain and Naruto as she was too far away to see.
 * A member of the clan also went along with Shikaku Nara and Inoichi Yamanaka when they formed scouting parties. He used his Byakugan and saw Naruto ahead of them.
 * Another member was shown speaking with Team Samui shortly after they enter the village informing them of what had just happened. He later tells that the village will soon start to enforce security.
 * A member that accompanied Team Kakashi and Ibiki to retrieve Riichi shown during the Konoha History Arc. He uses his Byakugan to confirm that the hostage was the real Riichi.

Trivia

 * means "Towards the Sun", and is the name of a city in the Miyazaki Prefecture in Japan.
 * The name "Eight Trigrams" is a reference to the Chinese martial art Baguazhang, a fighting style usually made up of circular movements, allowing the practitioner a wider range of motion and full use of momentum, without giving his or her opponent much of a chance for a direct strike. In Japan, it is known as Hakkeshō.
 * There were rumors that the Uchiha clan's Sharingan was descended from the Byakugan.
 * Ao of Kirigakure has defeated a member of the Hyūga clan, took the member's Byakugan and transplanted into his right eye.