Explaining…. Why Neji love Karui (according to meh :D)
Neji is used to people obeying him. His teammates, his subordinates, even his sensei. So when Karui refused to listen, he was immediately intrigued. Why wouldn't she listen to him? And why couldn't he hate her because of it? What made her different? He noticed this that first time they were together, on the mountain. Neji is used to women wanting to cling to him, wanting to him to hold them. When Karui refused any contact with him, he was taken aback. And that is why he pursued her; to figure her out.
That second night, in the glade by the river, Neji was having fun; half-joking about wanting to make her his girlfriend. He wanted to probe her, feel her out (not in a secual manner you freaks XD) And he thought being in a relationship with her would make his psychoanalyzing easier. His theory was that she would be like any other girl and become insipid, boring. He was only playing a game. But then everything changed in that on emoment Karui revealed her true reasoning to him about why she was so averse to a relationship. It reminded him of his own self and his trust issues (not to mention they were, for all intents and purposes, orphans, and could relate to that loneliness; and fuck the police, I don't care if Neji's uncle is technically the reason Karui's dad is dead, which then led to Hizashi's death and they really shouldn't be bonding over anything because I DECIDED THAT THEY CAN LOOK PAST THAT :'D). And suddenly, this wasn't a game anymore. He saw a side of Karui that night that changed the way he felt about relationships and love in general. (This is also when Neji began to develop those feelings he couldn't quite recognize as love yet)
When Neji got sick, and Karui took care of him, he thought of her as the caring, motherly influence he had never had growing up. She helped show him what it truly meant to care for someone selflessly, a concept that was foreign to was another side of Karui Neji had never seen, and he was positive no one else had either, which made him feel an even deeper emotion, one he still couldn't name. But that moment in the shower, as he began to lose his balance and Karui didn't even hesitate to jumpto his aid (and then sincere concern and compassion he saw in her face) presented another dramatic emotional shift in this relationship. It would be a lie to say he didn't feel loved at home, with his friends and teammates. Neji would do anything for them, and he knew they felt the same about him. But in that moment, when Karui looked at him with such blatant concern on her face, not caring about anything else but his well-being and safety, he felt like the most important person in the world. Coming from a clan who considered him second-class at best, and a worthless waste of space at worse, this had a huge emotional toll on Neji. From that moment on, he considered her truly his, and his protective instincts took over. He wanted her to feel as loved and wanted as she had mande him feel in that moment. (That night they spent together, when he told her he loved her, he wasn't even thinking, the words just came to him naturally and he said them unconsciously. He didn't regret it in the morning, though.)
Neji is naturally averse to change. So naturally, his time spent in Kumo unsettled him, although Karui was an intensely calming influence on him, keeping him grounded. When he returned to Konoha, knowing Karui was coming too, he visibly relaxed. When she came to stay with him, there were still doubts; he could sense them. He really didn't mind; Neji merely wanted to be close to her (born out of that previous relationship shift in Kumo) and didn't expect anything from her. But when the subject of choosing between Karui and his village came up, Neji faltered. He realized he couldn't decide. He couldn't tell Karui he would not hesitate to sacrifice her to keep his village safe, nor could he tell her he would let the Leaf fall to keep her safe, because they were both lies; Neji hates lying. (*Little known fact: one thing Hyuuga Neji hates is when someone is disingenuous, therefore he is always honest.) He would never jeopardize the lives of his friends for someone, and he definitely wasn't about to lose Karui; again, his protective instincts took over, and he formulated an ideal situation, one that was honest. (Neji is no coward, nor does he shirk his responsibilities. He is chivalrous and always steps up to the plate, going all the way for his friends…just letting you know :P) He was willing to sacrifice himself to keep both his village and Karui safe. He was used to sacrificing himself; he is second-branch. He is also used to everyone just accepting that fact, however unfair the believed it to be. Hinata, his uncle, his friends and teammates, even his sensei all knew what fate was expected of him should a situation ever occur in which Hianta was in danger: he would be expected to give his own life to save hers. So when Karui lashed out at him for saying he would easily give up his life for hers, he was genuinely surprised. This presented another relationship shift. Never before had someone acknowledged his right to live as a human being, or questioned his fate. He himself hadn't done that either. When Karui placed value on his life that day, Neji saw himself in a different light. She had made him feel wanted…again. Any doubt he held in his mind before dissolved in that moment. Even if they hadn't, those three words she said to him would have done the trick: I love you.
The day Hiashi came to visit is one Neji will never forget. As soon as he opened the door, he knew everything was about to change. But let's clarify first. Hiashi doesn't care what Neji does. He's only second-branch, therefore his personal life is of no consequence to Hiashi or the main branch, as long as it doesn't interfere with his duty to Hinata. And when he heard from Ino (lol sorry Bee but I'm sticking to that story; seems legit and IC for her 3) that Neji was seeing her 'best friend,' he truly had no intention of ruining his life. (He really did think is was Tenten.) He was curious, like everyone else, as to who had managed to snag his cold nephew. But when Hiashi saw Karui, her tell-tale dark skin and the Kumo hitai-ate on the table, he knew this was more serious than he had thought. Now, back to Neji. He knew he was in big trouble the moment his uncle saw Karui. Had she been anyone else, it would have been ok. But because she was from Kumo, the village who caused Hizashi's death in Hiashi's eyes, this was unacceptable. Neji knew the entire situation was incredibly volatile, prone to explosions at any moment. He knew neither Hiashi nor Karui would bend to the other's will, resulting in one of them getting hurt. Knowing Hiashi's strength, Neji predicted a grim outcome. So he did what came naturally: compromise his own safety to spare a disastrous confrontation. He attacked Hiashi, deflecting attention from Karui if only by a few precious moments (when he assumed she would actually listen to him and just go…he should have known better, eh?). He paid for it dearly (more so than he would let Karui know) but he achieved his goal. She was no longer in immediate danger. (He had reservations about this plan, however. He didn't want Karui to see him in such a vulnerable state. He also didn't want her to see, with her own eyes, how much power Hiashi and the main branch really had over him.) When Hiashi finally took his leave, telling Neji the elders would want to see him, he felt a pang of fear for the first time. (not that he would let Karui know that either.) He had been pushed to the brink of death before by the elders, for minor things, the worst time being the "punishment" he had received for his prelim match with Hinata during the Chuunin Exams. (I'm not sure if that actually happened, but it seems legit, so I'll pretend it did.) It had taken him months to recover. For this offense, disrespecting Hiashi, consorting with "the enemy," refusing his destiny, he knew the punishment would be severe. When he told Karui his life was insignificant enough to the elders, he didn't tell the complete truth. His life was insignificant enough to them that they would kill him and feel no remorse. If he met with the elders the next day, there was a high possibility of not returning alive, leaving nothing standing in their way of getting to Karui. He knew she had to leave for her own safety, but he was loathe to let her go. Not without him. He had grown accustomed to her constant presence; it assured him everything was ok. (….Ok and then they were lovey dovey and they went to Kumo together and I ran out of things to say here but yeah _)
The proposal. Wow. Okay, a lot of factors went into this, the most immediate one being the confrontation with Hiashi. Not only did Neji realize how short his life could be, being prone to having it cut off at the whim of others, but he also realized how often his life had been screwed over by somebody. He was never happy; he had never been happy. But around Karui, he was. He was completely different. She changed him, saving him from himself essentially. This was not something Neji took lightly. No one had made him feel so carefree, so loved, so simply happy in his entire life, not like Karui did. He wouldn't, no, couldn't, lose that in his life. Not after knowing what that happiness felt like. Similarly, now he also knew how easy it would be for Karui to just walk out of his life. Granted, she had threatened to leave without him to protect him but if she had a mind to, she could leave, and never come back. Neji didn't want to risk that. But don't mistake him: he didn't ask Karui to marry him out of a selfish need to possess her. Hiashi's visit was the kick that jolted him into the realization that he really couldn't live without Karui. Thus, a proposal.
:'D