Another plot could be that the fusion with Kyuubi allows Naruto to access some long - forgotten or hidden knowledge about the ninja world. Maybe there are secrets about the origin of chakra or ancient jutsu that are locked within the Kyuubi's essence. Naruto then embarks on a journey to uncover these secrets, with his friends by his side, and in the process, he not only becomes more powerful but also discovers more about the history of the ninja world.
Another possible plot is that Naruto struggles with the Kyuubi's instincts within his new body. He has to balance his own values and will with the primal urges of the Kyuubi. This internal conflict could be really fascinating as he tries to stay true to himself while harnessing the power of the Kyuubi body, and it could also lead to some character development where he becomes even more self - aware and in control of his emotions and powers.
A possible plot is that the Fem Nibi and Fem Kyuubi are reincarnated in human forms and they meet Naruto by chance. They initially don't remember their past as tailed beasts but feel a strange connection to Naruto. As they start to regain their memories, they discover that they have a shared destiny with Naruto to save the ninja world from a dark prophecy. Along the way, they have to overcome their own differences and learn to work together, all while Naruto is trying to figure out his feelings for these two unique characters.
One interesting plot could be Naruto using his unique bond with Kyuubi to help it regain its lost memories. Naruto might explore the Kyuubi's past and discover things that even the Kyuubi itself had forgotten. This could lead to new powers or a deeper understanding between them.
In some fanfictions, the Kyuubi's protection might lead to Naruto having a special bond with nature. Since the Kyuubi is a powerful force, it could influence Naruto's chakra in a way that makes him more attuned to the natural elements around him. This could give him an edge in battles, like being able to manipulate the environment in ways others can't.
One interesting plot is when the Kyuubi can communicate with Naruto's friends in a 'Fox Naruto Kyuubi' fanfiction. It creates a whole new dynamic as the friends have to deal with the powerful and often grumpy Kyuubi. Another plot is the Kyuubi being able to take a physical form outside of Naruto and having its own adventures while still being linked to Naruto. It's really cool to see the Kyuubi interact with the ninja world on its own terms.
One interesting plot could be the Kyuubi's influence on Naruto's relationships in the harem. For example, the Kyuubi's power might attract some characters who are interested in that power, leading to unique interactions. Another plot could be Naruto having to balance his newfound harem with his ninja duties, and the Kyuubi sometimes interfering or helping in these situations.
Another plot could be Kyuubi teaching Naruto some ancient and forgotten ninja techniques. As a powerful and ancient being, Kyuubi might know some techniques that have been lost over time. Naruto could then use these new techniques to surprise his opponents in battles and also contribute to the growth of the ninja arts in the village.
One interesting plot could be Naruto learning to control the Kyuubi's power in unique ways that are different from the original story. For example, he might be able to use the Kyuubi's chakra to create new jutsu that are a combination of his own skills and the Kyuubi's raw power.
One interesting plot could be their initial encounter. Maybe Madara discovers the power of the Kyuubi and tries to form an alliance with it. This could lead to a series of adventures where they face common enemies together.
One possible plot could be Naruto gradually realizing his feelings for Fem Kyuubi as they go through various adventures together. Maybe they start off as friends but as they face more and more challenges, like fighting powerful enemies, their bond deepens into love.