Obviously Naruto himself is a very popular character in 'naruto kyuubi child fanfic'. He is the main focus as the host of the Kyuubi. The Kyuubi is also quite popular as it is such a powerful and mysterious entity within Naruto. Then there's Iruka, Naruto's teacher. He often plays an important role in fanfics as he is one of the first people to show kindness to Naruto as a child. And Sakura might also be a popular character, as her relationship with Naruto can be explored in different ways in these fanfics, especially when Naruto is still a child dealing with the Kyuubi's influence.
Well, in some 'naruto kyuubi child fanfic', the focus might be on how Naruto's life changes when he first realizes the presence of the Kyuubi within him as a child. Maybe he starts having strange dreams that are actually the Kyuubi's memories. Or perhaps he finds that he can draw on a small amount of the Kyuubi's power without fully transforming, which he uses to win a small local competition in the village. There could also be a story where the Kyuubi's chakra affects Naruto's growth, making him grow faster physically or mentally in some aspects as a child.
Naruto would likely be a very protective father. He would teach the child about the power of the Kyuubi and how to control it. The Kyuubi, although a powerful and somewhat wild entity, might have a soft spot for the child as it is a part of itself. The child would look up to Naruto and also be in awe of the Kyuubi's power within them.
The plot could involve the child being sought after by various ninja clans who want to use the power of the Kyuubi within the child for their own purposes. The child, with Naruto's teachings, resists and tries to find a way to use the power for the good of the village. Maybe the child discovers a new form of chakra control that combines Naruto's Uzumaki heritage and the Kyuubi's power.
No. In the Naruto series, Naruto is the host of the Kyuubi, not its slave. Fanfics might deviate from the original concept, but in the official story, Naruto has a symbiotic relationship with the Kyuubi. He gains power from it and eventually befriends the Kyuubi spirit.
Well, Kyuubi might be possessive of Naruto because they have a unique bond. Kyuubi has been inside Naruto for a long time. They've shared experiences, and Kyuubi may see Naruto as its own in a way. Also, Naruto has sort of tamed Kyuubi to an extent, and this might make Kyuubi feel like Naruto is special to it, so it shows possessiveness.
One great Fem Naruto Kyuubi fanfic is 'The Nine - Tailed Fox's New Host'. It explores how a female Naruto deals with the power of the Kyuubi in a unique way. The story focuses on her training and how she overcomes various challenges with the help of the Kyuubi's power.
One possible aspect could be a story about Naruto befriending the female Kyuubi. In many fanfics, they might start with Naruto trying to understand the Kyuubi's female form better. Maybe he discovers that she has a different personality compared to what he expected from the regular Kyuubi. For example, she could be more gentle and protective in a way that surprises Naruto.
Yes. In many Naruto fanfics, Kyuubi plays a significant role. Since it's so closely tied to Naruto, it can easily be made to serve the fanfic. It might be used to introduce new characters who are interested in the Kyuubi's power. Or perhaps the fanfic is set in a different timeline where the Kyuubi has a different relationship with Naruto and has to serve in a way to protect the village or Naruto himself.