One possible plot could be that Naruto and Sasuke, having grown up together, become the ultimate team in protecting the Hidden Leaf. They combine their skills and knowledge to face new threats that are far more powerful than anything they've encountered before. They might also have a deeper understanding of each other's past traumas and work together to heal those wounds while strengthening the village.
Maybe they embark on an adventure to help a small, oppressed village. They use their combined skills to overthrow the tyrant ruling the village and then stay for a while to help rebuild it. During this time, they learn about different ways of life and make new friends. This adventure would strengthen their bond and also their reputations as great shinobi.
Well, it could be that as they grow up, Hinata becomes an important part of Naruto's support system. She's always there for him when he has doubts about his role as Hokage. Naruto, on the other hand, encourages Hinata to take on more leadership roles in the Hyuga clan. Their relationship blossoms as they grow both individually and together, and they might get married and have a family, with their children being trained in the ways of the ninja, carrying on their legacies.
As they grow up together, Hinata would be constantly by Naruto's side during his journey to become Hokage. She would offer him emotional support and practical advice. Naruto, being the kind - hearted person he is, would gradually fall in love with Hinata's selfless love for him. Their relationship would develop as they face the challenges of the ninja world together, and eventually, they would be in a loving, committed relationship.
Definitely Naruto and his friends like Shikamaru. Shikamaru, being the smart strategist, often plays a role in helping Naruto make important decisions as an adult in fanfiction. Also, characters like Kakashi might still be around in some fanfictions, acting as a mentor or an advisor to Naruto in his adult leadership role. And of course, the new generation of shinobi such as Boruto may also be included, showing the relationship between Naruto as a father and his son.
In a 'naruto and hinata grown up fanfiction', perhaps they go on adventures outside of the village. Naruto has always been curious about the world, and now with Hinata by his side, they explore different lands. Along the way, they meet new friends and foes, and Hinata's gentle yet strong nature helps them out of many difficult situations.
One interesting Naruto grown up fanfiction could be about Naruto becoming a great Hokage and how he manages international relations. Another might focus on his family life with Hinata and how they raise their children in a post - war Konoha.
One possible reason could be that Naruto realizes Sasuke is too far gone in his quest for revenge. Naruto might see that no matter how much he tries, Sasuke won't change his ways, so he gives up. For example, if Sasuke keeps attacking innocent people in his pursuit of power to defeat Itachi's enemies, Naruto might finally lose hope.
One idea could be that Naruto and Sasuke team up to face a new and powerful enemy from a different dimension. This enemy has the ability to manipulate time, which throws the entire ninja world into chaos. Naruto and Sasuke, with their combined skills and understanding of each other, start to figure out the enemy's weaknesses. They have to rely on Naruto's Rasengan and Sage Mode, along with Sasuke's Sharingan and Rinnegan powers. Their journey to stop this enemy also involves them reconciling some of their past differences more deeply as they face challenges together.
Maybe a young apprentice of Hinata. A girl who is inspired by Hinata's grace and strength. This character could bring a fresh dynamic as she looks up to Hinata and also gets to know Naruto. Additionally, there could be a mysterious figure from a far - off land who comes to the Hidden Leaf and has an unexpected connection to Naruto and Hinata's story.