Well, a common theme is the power of their bond. In these fanfictions, it's often shown that their connection gives them strength. They might be able to achieve things together that they couldn't alone. It could be about them teaming up against powerful enemies, with their relationship as a yaoi relationship adding an extra layer of complexity and motivation to their actions.
Another option could be FanFiction.net. However, be aware that not all types of content are allowed on every site. Some fanfictions might be removed due to violating the site's terms. You should also check the rating and description of the fanfictions to make sure they are appropriate for you.
Writers will sometimes create internal monologues for the characters. Neji might be thinking about how Naruto is different from what he expected, and Naruto could be thinking about how cool Neji is. They also use the idea of shared experiences. For instance, going on a difficult mission together and how that experience changes their relationship. They might start to understand each other's pain and hopes, which in turn shows their chemistry in the fanfiction.
For some fans, the unique relationship between Naruto and Neji in the original Naruto series is what draws them to this type of fanfiction. The idea of exploring a different, more romantic or intense connection between the two characters can be exciting.
One popular theme is friendship. Since Naruto is known for his ability to befriend almost anyone, when Neji is female, it can add a new layer to their friendship. They can support each other in different ways, like Naruto inspiring female Neji to break free from the constraints of her clan, and Neji being there for Naruto during his tough times.
One popular theme is the idea of redemption. Orochimaru is a character who has done many bad things, and in yaoi fanfiction with Naruto, Naruto could be the catalyst for Orochimaru's change. Another theme is the exploration of power differences. Naruto is very powerful in his own right, and Orochimaru is also extremely strong and cunning. Their relationship in fanfiction can play around with who has the upper hand at different times.
There's 'Hidden Feelings'. In this fanfic, the author focuses on the unspoken emotions between Naruto and Neji. It's a shorter piece but manages to capture the essence of their potential relationship quite well. It's a quick and interesting read.
One possible theme could be family loyalty. Given their relation as part of the Hyuga clan, the fanfiction might explore how their relationship affects their loyalty to the clan. Another theme could be love and sacrifice. Neji was always very protective of Hinata in the original series, and this could be expanded upon in a romantic context in the fanfiction.
One of the main themes is probably the clash and then the coming together of their personalities. Naruto is so full of life and optimism, while Zabuza has that dark, brooding nature. In fanfiction, this contrast often leads to some really interesting character development. Also, loyalty can be a theme. Zabuza has his own sense of loyalty to his goals and people like Haku, and Naruto has his loyalty to his friends and village. When these two loyalties interact in the fanfiction, it creates a lot of drama.
Themes like loyalty and sacrifice are often seen. They are loyal to their village and to each other. There could be a situation where one sacrifices for the other. Additionally, the exploration of their different ninja techniques and how they can combine them is also a theme. It's fascinating to see how fanfiction writers play with their abilities and create new strategies for them in various scenarios.
One popular theme is their growth as shinobi. It could be about how Naruto learns new jutsus from Kakashi and becomes stronger. Another theme is their bond as comrades. They support each other during tough times in the village.