Another idea is that Naruto and Hinata go missing - nin to explore a dark power that is threatening the ninja world but is being ignored by their village. They sacrifice their status in the village to do what they think is right. Their relationship deepens as they face the difficulties and moral dilemmas together.
One popular storyline could be about a missing nin who has a change of heart and tries to secretly protect the Hidden Leaf. Another might involve a missing nin with a unique power that the various ninja villages are trying to either recruit or eliminate. There could also be stories where a missing nin is on a quest for redemption after being wrongly accused.
In many of these fanfictions, the danger they face as missing - nin forces them to communicate on a deeper level. Hinata, who has always been shy around Naruto, becomes more assertive in expressing her feelings. Naruto, in turn, becomes more protective and understanding of Hinata. They grow together through the various challenges like fighting off other ninjas who are after them.
Sasuke is often a popular character in such fanfictions. His initial departure from the village makes him a prime example of a missing - nin. Writers like to explore his journey further, what he experiences outside the village, and how his relationships change.
Sasuke is often a popular one. In fanfiction, his journey as a missing - nin and potential connection to Akatsuki can be explored in many ways. His power and his complex relationship with Naruto make him a fascinating character to write about in this context.
Sasuke Uchiha is often a popular S - rank missing - nin in fanfiction. His defection from Konoha makes him a prime candidate for such stories. Orochimaru is another. His thirst for knowledge and power led him to become a missing - nin, and his abilities and mysterious nature are great fodder for fanfiction. Then there's Kakuzu. His unique jutsu and long life as a missing - nin give writers a lot to work with.
Perhaps the missing nin discovers new abilities within the Rinnegan that no one else has. They might be able to combine different paths in unexpected ways. For instance, using the Animal Path to summon creatures and then enhancing those creatures with the power of the Asura Path. This would make their summoned beasts more powerful and difficult to defeat in combat.
If Naruto and Temari were missing nin in a fanfiction, it could start with a misunderstanding. Naruto might be framed for a crime he didn't commit and Temari, believing in his innocence, decides to help him escape. They then have to live on the run. Along the way, they meet other outcasts and form a sort of rebel group. Naruto's ability to make friends easily and Temari's strong leadership skills could be the driving force behind this new group's growth.
Kimimaro could be an interesting missing nin character to explore in fanfiction. He was a tool for Orochimaru, but had his own internal struggles. You could write about his life before fully becoming a missing nin, his loyalty to Orochimaru despite his own deteriorating health, and what might have happened if he had broken free from Orochimaru's control. Another character could be Nagato. Before he became Pain, he had experiences that could be considered as leading towards a missing - nin - like existence. His views on peace and his use of the Akatsuki could be delved into in the context of a missing nin story.
One great source for Naruto and Hinata fanfiction could be FanFiction.net. You can search for stories specifically focused on their relationship there. There are often new and interesting takes on their story, from how they first fell in love to their married life in the future.
One possible fanfiction could be about Sasuke becoming a missing nin again. Naruto and Sakura, now more powerful, set out to find him. They face many challenges on their journey, like dealing with other villages that want Sasuke for their own purposes. Naruto still believes in saving Sasuke from the darkness that led him to become a missing nin in the first place.