Some fanfictions focus on the characters' growth after the main story ends. For instance, Naruto and Hinata could be dealing with the challenges of raising their family while also having to face a new threat to the village. Sakura might be training a new generation of medical ninja and has to deal with a difficult student. Sasuke could be traveling the world again, but this time with a purpose of sharing his knowledge and skills with other ninja. These post - series plot ideas can explore the characters in new and interesting ways.
A plot could involve time travel. Naruto and Hinata find themselves sent back in time, and they have to find a way to get back to their own time. Along the way, they meet a younger Sasuke and Sakura. This gives Naruto a chance to try and prevent some of the bad things that happened in Sasuke's past, and Hinata can bond with a younger Sakura, sharing her own experiences of growing up shy and how she overcame it.
One idea could be a story where Sasuke and Naruto have to team up again for a dangerous mission, and Hinata and Sakura also join in. During the mission, Hinata might use her Byakugan to detect hidden enemies, while Sakura uses her medical and combat skills to support the team. And Sasuke and Naruto could have some deep conversations about their past and future, like they did in the original series.
A great plot twist could be that Sasuke suddenly loses his sharingan and has to rely on his other skills and the help of the others. Naruto might have to train Sasuke all over again, and Hinata and Sakura could be involved in finding a way to restore Sasuke's sharingan. It would change the dynamics of their relationships and how they interact with each other.
One of the most popular themes is romance. Fans love to explore the different possible relationships between Naruto, Hinata, Sasuke, and Sakura. For example, there are many fanfictions that focus on the development of Naruto and Hinata's relationship further, or the complicated love triangle between Sasuke, Sakura, and Naruto. Another theme is friendship. These characters have a long history together, and fanfictions often show how their bonds of friendship are tested and strengthened over time.
One possible plot could be a friendly sparring match. Naruto and Hinata are one team, and Sasuke and Sakura are the other. They start off with basic jutsu and gradually escalate as they try to outdo each other. There could be some friendly banter between Naruto and Sasuke, and Hinata and Sakura could also have their moments of showing off their skills.
In a fanfiction, there could be a story where a mysterious enemy targets Sasuke, Naruto and Sakura specifically because of their unique bond. The three of them then have to go into hiding and figure out who the enemy is and what they want. Along the way, they rely on each other's strengths and grow even closer as friends.
One idea could be a story where Sasuke, Hinata and Naruto are on a joint mission. Naruto's cheerfulness, Hinata's gentle strength, and Sasuke's brooding nature create an interesting dynamic. They face a powerful enemy and have to learn to combine their unique skills, like Naruto's Rasengan, Hinata's Gentle Fist, and Sasuke's Chidori, to defeat it.
One idea could be a mission where Naruto, Sakura, and Hinata have to infiltrate an enemy stronghold. Naruto uses his shadow clones for distraction, Sakura provides medical backup and uses her strength in combat, and Hinata uses her Byakugan to detect hidden traps. Another could be a story set in a post - war Konoha where they work together to rebuild and also deal with the emotional traumas of the war. They could also go on a journey to find a lost ninja art that was once from Konoha but was stolen long ago.
How about a story set in an alternate universe where Sasuke and Hinata are arranged to be married? Naruto then tries to break the arrangement because he realizes his true feelings for Hinata. This would create a whole new set of relationships and conflicts among the three.
One plot idea could be Sai trying to understand the deep bond between Naruto, Sakura and Sasuke. He might initially struggle as he has his own unique upbringing. For example, he could be assigned a mission with the three of them and slowly learn about their history, like Naruto's determination to bring Sasuke back and Sakura's unrequited love for Sasuke in the beginning. This could lead to Sai having a new perspective on friendship and loyalty.