One possible plot could be Naruto's journey of self - discovery as he tries to come to terms with being left behind. He might find hidden strengths within himself. Another could be him forming unexpected alliances with other characters who also have a sense of being alone. For example, he could team up with a wandering ninja who has his own story of abandonment.
Well, in some fanfictions, Naruto may start to explore his family's past more deeply after feeling left behind. He could discover secrets about his parents that were previously unknown. This could lead to him having new goals, like reclaiming his family's honor or finding out why they seemingly abandoned him. It might also involve him getting in touch with relatives he didn't know he had.
In this type of fanfiction, a common plot is Naruto's struggle with his emotions. He is constantly feeling the pain of being left behind. So, he might pour his energy into training harder than ever. As a result, he could develop new and powerful jutsu. He may also start to question the village's role in his situation, which could lead to some interesting confrontations with the village elders or other authority figures.
A plot could be Naruto being tied up by a powerful new enemy who has a personal vendetta against him. This enemy might be from a clan that Naruto unknowingly wronged in the past. In the fanfiction, Naruto's friends would then have to race against time to find and rescue him. Or perhaps Naruto is tied up in a magically - enhanced trap set by a dark sorcerer who wants to use Naruto's chakra for their own evil purposes. His friends would need to figure out how to break the spell and free him.
One interesting plot could be the growth of their children. For example, how they inherit the ninja skills from Naruto and Hinata and face their own challenges in the ninja world. Another plot might be the family's role in maintaining peace between different ninja villages. They could use their influence to promote cooperation.
Perhaps in this fanfiction, Naruto's family leaves him because they fear his godlike abilities. Naruto then has to prove that he can use his powers for good. He could start by helping the villagers who once shunned him. This would lead to a series of events where he gradually gains the respect and understanding of those around him, despite his family's absence.
One interesting plot could be about their family vacations. Maybe they go to a hidden hot spring village and Naruto and Hinata have to deal with Boruto and Himawari getting into little misadventures there.
In some fanfictions, the banished family might be wrongly accused. So in this case, they could be on a journey to clear their name. Along the way, they encounter Naruto and team up with him. They might face many challenges together, like fighting against other rogue ninja groups who want to take advantage of their situation. This would create a story full of action and adventure.
In a Naruto and One Piece crossover fanfiction with this theme, Naruto could be found by the Straw Hat Pirates after being abandoned. Luffy might see Naruto's strength and determination and invite him to join the crew. Naruto would then have to navigate the Grand Line, using his ninja abilities in a world full of pirates. It could also lead to some interesting battles where Naruto's jutsu combines with the Devil Fruit powers of the crew members.
A new character could be an old friend of Naruto's parents who shows up. They might have some information about his family and why he was left behind. Maybe there's a healer who tries to help Naruto deal with the emotional scars of being left behind. This healer could have their own backstory related to loss and abandonment as well.
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 really cool concept would be if Percy, while left behind, enters a different dimension or parallel world. In this new world, he has to adapt to different rules and face new challenges. This could lead to some really exciting adventures and character development as he tries to find his way back to his original world and reunite with his friends.
One interesting concept could be the merging of different character personalities. For example, if a character from 'Left Behind' is crossed over with a character from another series, their contrasting beliefs and values can create engaging storylines. Maybe a character who is very religious in 'Left Behind' meets a more skeptical character from another story, leading to debates and growth for both.