Another theme is identity. Naruto has to balance his own identity with the influence of the full - blooded Kyuubi within him. Some fanfictions explore how this affects his relationships with others, like his friends and the villagers who once feared him because of the Kyuubi.
One common theme is the power struggle. It often shows Naruto trying to control the Kyuubi's power, which can be overwhelming at times. Another theme is friendship. Despite the initial hostility between Naruto and the Kyuubi, many fanfictions explore how they can become friends or at least allies.
One common theme is power. How Naruto's connection to the Kyuubi gives him extraordinary abilities. Another is identity, as he has to figure out where he ends and the Kyuubi begins.
A frequent theme is trust - building. Given their complex relationship in the original story, in fanfiction, they usually have to work on building a deeper trust with each other. Another theme could be the exploration of Kyuubi's past. Sometimes, Naruto gets to learn more about Kyuubi's history and origins, which in turn affects their relationship. Also, there are stories where they face external threats together, which further cements their bond as mates.
One common theme is the struggle for acceptance. Naruto as a kid with the Kyuubi inside him is often shunned by the villagers, so the fanfiction may explore how he deals with that. Another theme is the power within. How Naruto as a young boy learns to control and use the Kyuubi's power is a big part of these stories.
Another theme is power and control. In these fanfictions, the fem Kyuubi may have different levels of power and the story might revolve around how Naruto and she manage or share that power. For example, they could be working together to master new jutsu that involve the Kyuubi's chakra in a more positive way. Also, the idea of acceptance is a theme. Naruto has to accept this new version of the Kyuubi and vice versa, which can lead to some really interesting character development arcs.
Power growth is a common theme. Since the Kyuubi is reborn, Naruto often experiences a new level of power. Another theme is redemption, as the Kyuubi may have a chance to atone for past actions. Also, the theme of friendship and partnership between Naruto and the reborn Kyuubi is quite prevalent.
One common theme is the exploration of Naruto's heritage. With the focus on his father in relation to the Kyuubi, it often delves into how his father's actions regarding the Kyuubi have shaped Naruto's life. For example, if his father made some sort of deal with the Kyuubi to protect the village and Naruto was an unintended consequence.
One common theme is the idea of acceptance. Naruto accepting Kyuubi as a part of himself and vice versa. Another is the theme of power. Since Kyuubi is a powerful entity, how Naruto's love for it affects his use of that power. Also, friendship is a theme, as their relationship can be seen as an unusual but strong friendship.
One common theme is power. How Naruto's new - found connection with the Kyuubi gives him extraordinary powers and how he uses or misuses them. Another is acceptance. Naruto has to deal with the fact that he is now more than just himself but also has this Kyuubi - like aspect, and how the people around him accept or reject this new version of him.
Well, power inheritance is a big theme. The grandson inherits not only Naruto's legacy but also the power related to the Kyuubi. This power can be both a blessing and a curse, which leads to the theme of self - discovery. He has to find out how to use this power in a way that benefits him and those around him. Additionally, there's often the theme of family secrets. There are secrets about the Kyuubi and Naruto's family that the grandson uncovers as the story progresses, which adds mystery and depth to the plot.