A really interesting plot idea could be that Kisame's sister has been in hiding all her life because of her unique abilities. Naruto stumbles upon her by accident. Her abilities are related to water, just like Kisame, but in a different and more positive way. For example, she can purify polluted water sources. Naruto convinces her to use her powers for the good of the villages. However, the Akatsuki wants to use her for their own evil purposes. So, Naruto has to fight to keep her safe and on the side of good. Along the way, they develop a deep friendship, and she becomes an important ally to Naruto in his fight against the forces of evil.
Well, a plot could involve Kisame's sister being a healer. Naruto gets seriously injured in a battle and she is the only one who can save him. As she heals him, they start to share their stories and dreams. This leads to her realizing that the Akatsuki's ways might not be right. Also, she could be in a love triangle between Naruto and a member of the Akatsuki, which would add a lot of drama to the story. There could also be a plot where she discovers a prophecy that Naruto is the key to saving the ninja world, and she decides to protect him at all costs.
One interesting plot could be that Naruto discovers a hidden power within Kisame's sword. Maybe during a battle, the sword starts to react to Naruto's chakra in an unexpected way, leading to a new form of combat for Naruto.
Another plot could revolve around Itachi and Kisame having a philosophical debate during a long journey. Since Itachi has his own complex moral code and Kisame is more straightforward in his loyalty to the Akatsuki, they could discuss the meaning of loyalty, power, and the end goals of their organization. This could lead to a deeper understanding between them or even a rift, depending on how the story unfolds.
One idea could be a story where Kisame and Sakura are forced to team up during a mission in a strange, new land. They start off distrusting each other but gradually learn to respect one another's skills. For example, Kisame is impressed by Sakura's medical ninjutsu when she heals him from a near - fatal wound. Another plot could be set in an alternate universe where they are both students at the ninja academy together, and their different personalities lead to some comical and also some heartfelt moments as they grow up.
One idea could be a story where Naruto and Kisame are forced to team up during a mission that has a greater threat to the ninja world. They start off distrusting each other but gradually come to respect one another's skills.
A really interesting plot could be a time - travel fanfiction. Suppose Sakura somehow travels back in time and meets a younger Kisame. She tries to change his path, knowing the future he will have. This could involve a lot of complex character development as Sakura has to deal with the differences in their values and the knowledge she has of his future actions.
One idea could be that Fem Kisame is a reformed Akatsuki member who teams up with Naruto to take on a new threat to the ninja world. They start off not trusting each other but gradually learn to respect and rely on one another as they face various challenges together.
One plot idea could be a story where Kisame and Itachi are on a mission together in a mysterious land. They encounter various challenges that test their loyalty to each other and their organization. As they face these difficulties, they start to understand each other on a deeper level, sharing their past traumas and dreams. This could build a strong bond between them without any inappropriate content, focusing more on their friendship and mutual respect.
One interesting plot could be Kisame and Naruto teaming up accidentally during a mission against a common enemy. They start off distrusting each other but gradually learn to respect each other's skills.
One idea could be that Harry, as Naruto's sister, discovers she has a unique form of magic that combines with Naruto's chakra. For example, she might be able to use her magic to enhance Naruto's shadow clone jutsu, making the clones more powerful and capable of different tasks. Another plot point could be that she tries to introduce the concept of Hogwarts and the wizarding world to the Hidden Leaf Village, which causes a stir as the villagers try to understand this new and strange form of power.
One idea could be a story where Naruto discovers he has a long - lost sister who has unique powers. They then team up to face a new and powerful enemy in the ninja world. Another could be a plot where the sister is from a different village and they have to overcome the differences between their villages to be together as family.