Hiashi Hyūga

is the head of the Hyuga Clan. He is the father of Hinata and Hanabi Hyuga, twin brother of the late Hizashi Hyuga, and uncle of Neji Hyuga.

Background
As the father of Hinata Hyuga and the uncle of Neji Hyuga, Hiashi has a significant role in the lives of his daughter and nephew.

Hiashi was born seconds before his twin brother Hizashi Hyuga, making him the head of Hyuga clan. The fact that Neji would never be able to succeed the clan, and that he would be marked with a curse mark so that he could be disciplined caused friction between the brothers.

On Neji’s fourth birthday, Hiashi personally placed Neji’s seal on him. When his daughter, Hinata, was kidnapped by a the Head Ninja of Kumogakure no sato, who was acting as an ambassador to Konoha at the time, he had no choice but to kill her kidnapper. The Land of Lightning overlooked the kidnapping, and they demanded a life for a life, asking Hiashi surrender his life and be killed, or else a new wave of warfare between the Hidden Leaf and Cloud villages. While Hiashi planned on accepting the punishment, the Hyuga Clan elders new this was merely another attempt by the Land of Lightning to get their hands on the Byakuga. The elders instead suggested that Hizashi go in his place as not only could they claim it was killed the Lightning Ninja, but it would be impossible to get any information from Hizashi's body thanks to his curse mark. Hiashi immediately refused the idea, until Hizashi stepped forward revealing that it was his idea, saying that while he hated the main family's foolish laws, he wanted to save his brother and decide his own destiny. He asked Hiashi to tell Neji about his decision and his reasons before leaving to be killed.

Originally, Hiashi had trained Hinata to become the successor of the Hyuga Clan, but Hinata’s lack of confidence ultimately led him to deciding she was not worthy and instead turned his attention to his younger daughter Hanabi while leaving Hinata in Kurenai Yuhi’s care.

Personality
Hiashi's general personality is very stern and strict, as he assigns both his daughters arduous training, rarely complimenting their performance. This is especially true with Hinata; when she was assigned to Kurenai Yuhi, he told her that he was unconcerned about the possibility that she would die, saying that the Hyuga Clan had no use for a weak successor. In truth, it was not that he felt Hinata's talent or potential was weak, but her drive to succeed was too weak to be the successor of the Hyuga Clan. Upon seeing her show true dedication, he began to openly cheer her on.

Chunin Exams
Hiashi made his first appearance outside a flashback at the Chunin Exams finals where he witnessed the battle between Naruto and his nephew. He was amazed at the true depths of Neji’s talent as he watch his already incredible mastery of the Gentle Fist teachings and access to some of their clan’s most powerful and secret techniques from simple observation. Neji’s battle went on, Hiashi sat silently as he watch Neji voice his deep hatred against the Main Family of the Hyuga Clan. After Neji lost to Naruto, and Neji seemed to have found himself in a crossway in his life from Naruto’s words, Hiashi felt now was the time to reveal Neji the truth of Hizashi’s death. After telling Neji revealing it to Neji, he gave Neji’s his father’s last words written on a scroll. Seeing that Neji accepted his words as the truth, Hiashi immediately bowing in apology, overwhelming Neji with emotion. Later during Orochimaru’s invasion, Hiashi showed his dedication to the village by fending off several Sound and Sand ninja with his Eight Trigram Great Heavenly Spin.

Filler arcs
Realizing that separating the Hyuga clan into 2 houses was causing a huge rift in the clan, Hiashi decided to as head of the clan to try and mend this. He began training Neji regularly in their clan’s full arts, something that was already considered a taboo by the rest of the Main House. His relationship with Hinata is seen improving, as he encourages her to do her best after seeing her more confident in herself.

Abilities
As the a member of the Hyuga clan, Hiashi possesses the Byakugan, which gives him an almost 360-degree field of vision, except for a small blindspot at the back of the neck. Also as the head of his clan, he is well-versed in all of his clan’s secret techniques. While the full extent of his prowess remains unknown, during Orochimaru’s invasion, Hiashi demonstrated tremendous skill by repelling several Sound and Sand ninja away with one attack.