One interesting storyline could be Naruto finding baby Sasuke alone in the forest and deciding to take care of him. Naruto, with his big heart, would do his best to protect Sasuke from any harm that might come their way, like facing off against wild animals or rogue ninjas.
In a fanfiction, it could be that baby Sasuke is lost in a different dimension, and Naruto somehow manages to cross over to that dimension to find him. Along the way, they encounter strange creatures and new forms of chakra. Naruto has to use his wits and strength to keep baby Sasuke safe and find a way back home.
One popular storyline could be Naruto finding baby Sasuke alone after a battle and taking it upon himself to protect him. Naruto might have to face various challenges while hiding Sasuke from those who would do him harm.
One interesting storyline could be Kakashi taking on a more fatherly role towards baby Naruto. He could teach Naruto some basic ninja skills from a very young age, like how to throw a kunai properly. This would create a strong bond between them early on.
One interesting storyline could be Kushina teaching baby Naruto some basic ninja skills in a really gentle and loving way. For example, she might show him how to throw a kunai softly so he doesn't hurt himself. Another could be their interactions with the other villagers. Maybe Kushina takes Naruto around the village to introduce him to the different shops and people, which would be really cute as baby Naruto would be all wide - eyed and curious.
Another could be a story where baby Naruto has a special connection with Kushina's chakra, and this connection helps him in some unexpected situations. Maybe when he is in a dangerous situation, the memory of Kushina's chakra within him gives him an extra boost to escape or fight back. Well, it could also be a story about Kushina protecting baby Naruto from some unknown threats within the village. There could be some secret enemies who are after Naruto for some reason, and Kushina uses all her skills and wits to keep him safe.
Some storylines could involve Minato's friends, like Jiraiya, interacting with baby Naruto. Jiraiya could be like an uncle figure and teach Naruto some unique things. There could also be a story where Minato shows Naruto the beautiful places in the village, like the waterfall where he used to train. And then there could be a plot where Minato has to make a difficult decision to protect Naruto from a greater threat, like a powerful enemy who wants to use Naruto for his own evil plans. This could lead to some really emotional and heroic moments in the fanfiction.
One interesting plot could be baby Naruto and baby Sasuke getting lost in the forest together. They have to rely on their budding instincts and nascent chakra to find their way back. Maybe they encounter some small, friendly forest creatures that help them. Another idea is that they accidentally switch places in the village for a day. This leads to chaos as the villagers react differently to them being in the wrong 'homes'.
One interesting scenario could be baby Sasuke and baby Naruto getting into innocent mischief together in the Hidden Leaf Village. Maybe they accidentally let all the chickens loose in the market area while playing a game of chase.
One interesting storyline could be a story where Sasuke, Naruto and Itachi have to team up against a new, powerful enemy. They put aside their differences and combine their unique skills. Naruto's positive energy and powerful jutsu, Sasuke's sharingan - based techniques, and Itachi's strategic mind make them a formidable force. This kind of story could explore their growth as characters and how they learn to trust each other more deeply.
Perhaps a fanfiction where Naruto and Sasuke are in a bit of a feud again, and Sai has to play the mediator. Sai, with his detached yet observant nature, tries to make Naruto and Sasuke see each other's points of view. This could lead to a series of events where they all grow as characters, learning about friendship, forgiveness, and the power of unity.
Another idea is that baby Sasuke and Naruto are found together by a third party, like a wandering ninja who decides to train them both from a very young age. This would create a different dynamic as they grow up together with a unique set of skills taught by this unknown mentor. They would probably have a stronger bond from the start compared to in the original story.