One idea could be a story where Naruto and Kakashi go on a special mission together in a mysterious land filled with new and dangerous enemies. They have to rely on each other's skills and develop a deeper understanding of their abilities.
A plot could revolve around Kakashi training Naruto in a very unique and unorthodox way. Maybe they go to a secluded place where Kakashi reveals some long - forgotten ninja techniques that were passed down in his family. This would not only strengthen Naruto's skills but also their bond.
Perhaps a story where Naruto gets trapped in a genjutsu that only Kakashi can break. However, Kakashi has to first figure out the source of the genjutsu. In the process, they both relive some of their past traumas and help each other overcome them, which in turn deepens their relationship.
One idea could be that Naruto joins the ANBU under Kakashi's strict training. He struggles to adapt to the ANBU's stealthy and often morally gray missions at first. For example, he might be conflicted when ordered to spy on a former ally. But with Kakashi's guidance, he learns to balance his ninja ideals with the demands of the ANBU.
One interesting plot idea could be that Kakashi's wife is a powerful ninja from a hidden village that was once an enemy of Konoha. She has to prove herself to the villagers, especially Naruto who is initially suspicious. Another idea is that she has a special ability related to sealing jutsu which helps in a major battle against a new threat. And perhaps she has a past connection to one of the Akatsuki members which adds a layer of mystery.
For Naruto's birthday, a plot could be that he wishes to spend it with his father, Minato, in some way. So he goes to the Hokage Rock and has a dream - like encounter with Minato's spirit. They have a conversation about Naruto's growth. For Kakashi, a plot could be that he gets a mysterious letter on his birthday. It leads him to an old training ground where he discovers a hidden memory of his father. The two stories could intersect when Naruto and Kakashi share their experiences with each other later.
A possible plot is that Naruto discovers a hidden power within Kakashi that even Kakashi was unaware of. This discovery leads them on a journey to explore the origin of this power. Maybe it's related to an ancient clan. As they dig deeper, their relationship grows stronger and they face many challenges together from enemies who also want this power.
One idea could be a story where young Kakashi has to protect a young Naruto from a group of rogue ninjas. It could show Kakashi's early skills and Naruto's innocent yet determined nature.
A really interesting plot for 'kakashi and naruto family fanfiction' could be that Kakashi accidentally stumbles upon a secret power within Naruto's family that has been dormant for generations. He then helps them unlock and control this power. Along the way, they form a stronger bond as a family. And as Kakashi is involved, he also rediscovers some of his own values and beliefs through this process.
One plot idea could be that the female Naruto has a special training session with Kakashi. During this, she discovers a new jutsu that Kakashi has been secretly working on. He decides to teach it to her because he sees her potential. This new jutsu then becomes crucial in a future battle against a powerful enemy.
One idea could be that little Naruto gets lost in the forest and Kakashi has to find him. Along the way, Kakashi discovers Naruto's secret hiding place filled with his dreams and wishes written on little scrolls.
One interesting plot idea could be Kakashi getting transported into a different Naruto timeline where all the villains have joined forces. He'd have to use his Sharingan and vast combat experience to survive and find a way to stop them. Another could be Naruto and Kakashi swapping bodies for a while. This would lead to some comical situations as Naruto tries to act like Kakashi and vice versa. Also, a crossover where Kakashi is sent to a parallel universe where Naruto doesn't exist, and he has to train a new group of ninja in the ways of Konoha.
One idea is that an enemy targets Kakashi's Sharingan and Naruto has to protect it. Along the way, Naruto learns more about the Sharingan's capabilities and how to use it against the enemy. This would be a great opportunity for Naruto to grow as a ninja and for their friendship to deepen.