One interesting plot could be that Kakashi and Naruto are somehow related through a convoluted family tree. This discovery could change their relationship entirely. They might start training together with a new purpose, not just for the sake of the village but also to understand their family heritage. Also, a plot could involve Kakashi protecting Naruto from a new threat that specifically targets the Uzumaki clan, which he now feels a closer connection to as part of this new family - like bond.
In some fanfictions, there might be a plot where Kakashi's past traumas are related to Naruto's current challenges. For instance, Kakashi's experience with losing his comrades could be used to help Naruto deal with the potential loss of his friends. Or perhaps a plot where Kakashi's family secrets are revealed and they have a significant impact on Naruto's growth as a ninja. This could involve a hidden jutsu or a prophecy that ties them together.
A possible plot could revolve around Kakashi's team members' reactions to Naruto being his son. For example, Obito's spirit (if it has any influence) might have mixed feelings. And in the story, Naruto might inherit some of Kakashi's unique abilities in a more natural way than in the original series. The fanfiction could also explore how the Akatsuki views Naruto differently, knowing he is Kakashi's son, and how that affects their plans to capture the nine - tailed beast within him.
One interesting plot could be a story where Sasuke and Sakura have a child, and Naruto and Kakashi become like uncles to the child. They all live in the same village and face new threats together, with the new generation learning from the old. For example, the child might inherit Sasuke's sharingan and Sakura's medical skills, and Naruto and Kakashi help train the child to be a great ninja.
A plot might involve Kakashi getting injured severely on a mission, and Sakura, in the process of taking care of him, realizes her true feelings for him. They then decide to get married. However, Kakashi's past traumas start to surface and affect their relationship. Sakura has to use her medical and emotional skills to help him through it. And in the end, they emerge stronger as a couple. There could also be a plot where an outside force tries to break them apart because they see their combined strength as a threat. But they fight against it and prove that their love is stronger.
One possible plot could be that Naruto's family, perhaps his father or mother, were actually alive but had to fake their deaths for some dark reason. Then they reappear and turn against Naruto, maybe because they are being controlled by an evil force. Another plot might be that his family had some long - hidden secrets that made them see Naruto as a threat to their real goals, so they betrayed him.
One possible plot could be that they are in a dangerous situation together, like facing a powerful enemy. In the heat of the moment, they realize their feelings for each other and share a kiss. Another plot could be that Tsunade is injured and Kakashi, while taking care of her, they have a tender moment and kiss.
One possible plot could be that they accidentally end up in a situation where Sakura becomes pregnant, and then they have to deal with the reactions of their friends and the ninja community. Another could be that it's part of a planned future for them, and the fanfiction focuses on their preparations for the baby.
One aspect of Naruto and Kakashi family fanfiction could be the idea of Kakashi mentoring Naruto not just as a sensei but as a family member. This could involve Kakashi helping Naruto understand the importance of family values, which Naruto lacks growing up. In fanfiction, we could see Kakashi inviting Naruto to family - like gatherings with Team 7, making Naruto feel more included and part of a family unit.
One possible motive could be to help Naruto control the Nine - Tails' chakra better. Hypnosis might be a way to reach into Naruto's subconscious and find a way to coexist with the powerful force inside him.
One possible reason could be that Kakashi is preoccupied with other important matters in the village. Maybe he has some top - secret missions or tasks assigned by the Hokage that demand his full attention, leaving him with little time to focus on Naruto.
One reason could be that he sees Naruto as a younger version of himself in some ways. Both have had their share of loneliness and challenges growing up. Kakashi may want to prevent Naruto from going through the same pain he did. Another reason is Naruto's importance to the village. As the jinchuriki of the Nine - Tails, Naruto is a key asset. Kakashi, being a loyal ninja, wants to protect the village's future which is tied to Naruto.