A common theme is the struggle against society. In these fanfics, the relationship between Naruto and fem Kyuubi might not be accepted by the villagers or other ninja. So they have to fight against the prejudice and norms of their society. Another theme is the exploration of the unknown. Naruto is entering a new territory with his feelings for the fem Kyuubi, and the fanfic often shows how he navigates this uncharted emotional landscape.
One common theme is redemption. Fem Kyuubi, often seen as a villain in the original story, gets a chance at redemption through her love for Naruto. Another theme is acceptance, as Naruto has to accept her for who she is, a tailed beast, and she has to accept his world of ninjas.
One common theme could be the exploration of power dynamics. Since Naruto is submissive in this concept, it might show how the Fem Kyuubi's power affects their relationship. Another theme could be character growth, as Naruto may have to learn and adapt in this new dynamic.
The theme of redemption can also be common. The fem Kyuubi may have a past that she is trying to overcome, and Naruto helps her in that journey. Also, the exploration of the unknown is a theme. The fem Kyuubi might have secrets about the ninja world that Naruto discovers as they interact more closely.
One common theme is the transformation of their relationship. It usually starts with Naruto having a more adversarial or at least a complex relationship with the Kyuubi due to its power, but as the female aspect is introduced, it turns into a love story. Another theme is acceptance. Naruto has to accept this new form of the Kyuubi and his feelings for her, and she has to accept his world and the fact that she's now in a different kind of relationship with him.
Love and loyalty are big themes too. The love between Naruto and the harem members, and their loyalty to each other. In many of these fanfics, they will face challenges that test their love and loyalty, like threats from outside forces or internal conflicts within the harem. And the fanfics often show how they overcome these challenges through their strong bonds.
Power and love is a common theme. Since Naruto is godlike, his power plays a role in the relationship. The female Kyuubi is also powerful. Their love often overcomes the differences in power levels. Another theme is acceptance. Naruto has to accept the female Kyuubi as she is, and vice versa.
In many 'naruto x fem foxy x fem kyuubi fanfic', the theme of redemption can be seen. Maybe the fem foxy or fem kyuubi characters have some sort of past they need to make up for. And Naruto, being the protagonist with a big heart, could be involved in their journey of redemption. Also, the theme of family or found family might be there. They could form a unique bond that is like a family, which is a really heartwarming aspect in some of these fan - created stories.
One common theme is the power dynamic. Since the Kyuubi is a powerful being, in fanfics, it can be about how Naruto and the Fem Kyuubi interact in terms of power sharing or how Naruto learns to control the power she represents.
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.
A great 'naruto falls in love with fem kyuubi fanfic' is 'Fem Kyuubi, Naruto's True Love'. In the fanfic, Naruto and fem Kyuubi's relationship begins in an unexpected way. Maybe she saves him in a dangerous situation, and from there, his feelings start to grow. The story delves deep into how they learn to understand each other's emotions and the unique bond that forms between them, which is different from Naruto's normal relationships with his friends.