A plot could revolve around Naruto trying to enter the Ninja Academy. He has to face all kinds of challenges, not just the physical tests but also the prejudice of the teachers. However, through his determination and some unexpected help from a kind - hearted shinobi, he manages to prove himself worthy of being a student at the academy.
Well, one possibility could be a crossover where Naruto somehow ends up in the world of Death the Kid. Maybe Naruto's chakra is mistaken for some kind of unique soul energy. And Death the Kid, being the perfectionist he is, might be intrigued by Naruto's unruly and yet powerful nature. They could team up to fight some common enemy that threatens both their worlds.
In this fanfiction, maybe the kid has some special power that Naruto notices. So Naruto adopts the kid to protect him from those who might misuse his power. Along the way, Naruto helps the kid come to terms with his power and they form a really strong bond, facing all kinds of challenges from other villages and ninja clans.
The plot could be that a kid from a small village is kidnapped by a group of ninjas from a rival village. Naruto hears about it and sets out on a journey to save the kid. Along the way, he overcomes various obstacles and battles the kidnappers to rescue the kid and return him safely home.
One possible plot could be that Kid Naruto gets lost in the forest and Kurenai, while on a mission, stumbles upon him. She decides to help him find his way back home. Along the way, Naruto shares his dreams of becoming Hokage with Kurenai, and she encourages him, seeing his determination.
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.
One idea could be a time - travel plot where Boruto goes back in time and meets kid Naruto. He could help Naruto in some of his early struggles and they form an unexpected friendship. This would also allow for some humorous moments as Boruto tries to explain modern things to Naruto.
In this fanfiction, the plot could be that Naruto's kid is kidnapped by an old enemy of Naruto's who wants to train the kid to be against the village. The kid has to use his wits and the little ninja training he has received so far to escape. Meanwhile, Naruto is on a desperate search for his child. This would create a lot of tension and also show how much Naruto has grown as a father compared to his own orphaned past.
Maybe he gets to relive his childhood but with a different mentor. Instead of Iruka, he could be mentored by someone like Kakashi right from the start. This would change his training methods and the way he approaches learning ninja skills. It could also lead to different relationships with his classmates as Kakashi might push him in different directions.
One possible plot could be that the Monkie Kid characters accidentally end up in the Ninjago realm. They meet the Ninja and at first there are misunderstandings as they don't know each other's powers and motives. But then they realize they have a common enemy, like an ancient evil that threatens both their worlds. So they team up, with the Monkie Kid using his magic staff and the Ninja using their elemental powers to fight this great evil.
Perhaps the kid is from a foreign land that Naruto visited during one of his missions. The kid could be an outcast in his own place because of some unique trait. Naruto, being the kind - hearted person he is, decides to adopt him. It could be that the kid has a different kind of chakra or a strange mark on his body that makes others afraid of him, but Naruto doesn't care.