A possible plot is that there is a prophecy stating that only Naruto with the Kyuubi's power and Sasuke together can save the ninja world from a coming disaster. They initially resist working together because of their past differences. But as they face various challenges along the way, they start to see the importance of their partnership. They train together, combining their unique abilities, and in the end, they are able to prevent the disaster.
Another plot could involve Naruto accidentally losing control of the Kyuubi's power and Sasuke being the only one who can calm him down. This could lead to a deeper understanding between them. They might then go on a journey to find a way to better control the Kyuubi's power so that Naruto doesn't endanger himself or others. It could also explore their relationship and how it has changed over time.
One plot idea could be Naruto and Sasuke having to team up again due to a new threat that is related to the Kyuubi's power. They have to learn to trust each other once more as they did in the past. Maybe there's a villain who wants to extract the Kyuubi from Naruto and use it for evil, and Sasuke has to protect Naruto while they figure out a way to stop the villain.
One idea could be exploring the bond between Naruto and the Kyuubi in a new way. For example, they could have a shared dream where they are in a strange, alternate world and have to work together to find a way back. Another plot could involve Naruto using the Kyuubi's power to save a village from a new, powerful enemy that no one else can defeat. And a third could be about the Kyuubi revealing a long - lost secret about Naruto's family that changes his perspective on his own powers.
Well, a plot could be that baby Naruto's presence starts to have an unexpected effect on Kyuubi. Kyuubi, who was once full of hatred, begins to feel a strange sense of attachment to the baby. As a result, Kyuubi starts to share some of its chakra with Naruto in a very small and controlled way, which gives Naruto some unique abilities even as a baby. And there could be a plot where other shinobi sense this strange chakra and start to investigate Naruto.
One idea could be Naruto fully embracing the Kyuubi's power and using it in unique ways. For example, he might be able to transform into a new, more powerful form that combines his own skills with the raw power of the Kyuubi. He could also use the Kyuubi's chakra to perform new jutsus that are previously unthinkable. Another plot idea is that Naruto starts to think and act more like the Kyuubi in some aspects, which causes conflict among his friends and allies as they try to figure out if he's still the same Naruto they know.
A possible plot is that the girl Kyuubi has a unique power that is the key to saving the Hidden Leaf Village. Naruto teams up with her to figure out how to use this power. Along the way, they encounter many challenges and also develop a romantic relationship. This could involve Naruto teaching her about human emotions and values as she was more used to her fox - like nature before.
In a fanfiction, Naruto could protect the Kyuubi when a new, unknown enemy emerges from a different dimension. This enemy has the ability to separate Naruto from the Kyuubi, which would be disastrous. Naruto has to not only fight this enemy physically but also strengthen his mental bond with the Kyuubi to prevent such a separation. He might also have to seek help from old friends and mentors, and together they form a shield around the Kyuubi to keep it safe.
One plot idea could be that Naruto, while possessed by the Kyuubi, has to face off against an old enemy of the Kyuubi from its past. The Kyuubi's power and Naruto's skills combine in unexpected ways, like Naruto being able to use the Kyuubi's chakra in more precise and strategic ways than ever before. Another idea is that the Kyuubi's memories start to merge with Naruto's, and he has to deal with the emotional turmoil of the Kyuubi's past traumas and experiences. This could lead to a whole new understanding of the relationship between Naruto and the Kyuubi.
One idea could be that Naruto, with the power of the Kyuubi, has to go on a special mission with Sakura. During the mission, they face a powerful enemy that can only be defeated by combining Naruto's brute strength from the Kyuubi and Sakura's medical ninjutsu in a unique way. For example, Sakura uses her medical skills to temporarily enhance Naruto's Kyuubi - influenced attacks, making them more precise and less draining on Naruto.
One idea could be that Naruto discovers a special leotard that has the power of the Kyuubi sealed within it. He then has to learn to control this newfound power while also facing off against enemies who want to steal the leotard for its power.
Maybe in the fanfiction, the Kyuubi has a soft spot for Hinata. Since Hinata is always so kind - hearted and gentle, the Kyuubi starts to protect her in its own way. This could create some interesting situations, like when Naruto is in danger, the Kyuubi takes over not just to save Naruto but also because it doesn't want Hinata to be sad. It would be a different take on the relationship between the three.
One plot idea could be that Naruto and Kyuubi have to work together to stop an ancient evil that is threatening the ninja world. This would require them to fully trust each other and combine their powers in new and unique ways.