Neji is a very complex Naruto Hentai character. At first we thought that he was cold as ice and that he was emotionally pretty much dead, but it all had it's reason. The reason for his extreme behavior not just towards Naruto Hentai, but to all other people he did know lies in his family ties. His family is divided into a main family were his girl cousin Hinata lives and the side family were he lives. The point of having a main and one side branch is so that one could fully concentrate on protecting the main. That way the preservation of ones genes could be kept at balance and everybody would have a task. Yet, Neji couldn't stand the fact that he was about to take a back seat and also he still thought at that time that his dad was sacrificed for the clans good just like that, but later on his uncle told him the truth and that his brother went on is own to protect the clan. The first time we saw Neji going fully out was in the first exam task where they had to fight against each other. His opponent was Hinata and at that point he wanted to show her who is the best fighter in there clan.
He had a clear upper hand in that battle and he won it pretty much with easy, even risking to kill sexy Hinata wasn't going to stop him to go forwards. Hinata was seriously injured at that time and Naruto was worried about her. That time he promised her tormentor to beat his ass next time they meet and who would guessed it Naruto Hentai had Neji as his first opponent in the final ninja exams. That battle was being fought in a huge Colosseum and of course all participants had buck fever. Still, now was the time what they learned from their hard and bloody ninja practice. At the beginning of the fight Neji looked like the clear winner, but Naruto gained more and more confidants after every hit he could lend on his enemy. Once Naruto went in beast mood he was all out and the other guy did stand no chance at all.
It was just a matter of time when the main hero would lend a knock out punch and so it was. The extreme chakra superiority forced Neji to his knees and the fight was over. After that fight Neji's uncle was talking about him regarding the matter of his father. He explained that it was his dads wish to be of use for the main clan. Everything that happened was based on his free will. After the battle with Naruto he began to understand what was going on around him. That was also the time when he decided to go to his uncles place and train even harder so that he could protect the family the same way his father did. He even reconciled with the so long hated cousin Hinata and he was aware that it wasn't her fault.
After that occasion we only saw Neji in action once and that was when a ninja group where he was part of started chasing after Sasuke who went to Oro to gain more power. There he fought in the middle of the forest against one of Orochimaru's underling and won, but he left battlefield nearly close to death so it was a really hard match for him. Everything past the first time skip was just chatting and we never really did saw him fight, before the big ninja war started. There he died in battle, protecting Hinata.