Well, they might go on an adventure to discover new jutsus. Sasuke could be on a mission to learn more about his clan's secrets and takes Naruto along for the ride because he knows Naruto's strength. Maybe they'll encounter powerful enemies and have to rely on each other to survive.
In this fanfiction, Sasuke may take Naruto with him to find a way to end all the hatred in the shinobi world. They could travel to different villages, meeting various characters along the way. They might learn about different cultures and ways of life, which could help them in their quest. And along the journey, their friendship could deepen even more as they face challenges together.
In this kind of fanfiction, Ace might take Luffy on an adventure to find a hidden treasure. They could encounter various powerful enemies and strange islands along the way.
In a fanfiction, they could be involved in a race. Naruto's speed, Sasuke's sharingan - enhanced perception, and Hinata's byakugan - aided navigation could all play a part. Maybe they start off competing against each other but then realize that there's an outside threat during the race. So they put aside their differences and work together to overcome the threat, forging a stronger bond in the process.
In this kind of fanfiction, one possibility is that they go on a journey to discover new jutsu together. They might leave the Hidden Leaf Village to find a place where they can train without the constraints of the village rules. Maybe they encounter new and powerful enemies that force them to rely on each other more than ever, strengthening their bond.
If they are cousins in fanfiction, it could change the whole dynamic of the ninja world. Their combined strength as family members could be a threat to their enemies. They might be able to use their family connection to bring peace to the villages in a different way. Maybe they could form a new kind of alliance based on family rather than just friendship or rivalry. And this could inspire other ninja clans to also seek peace through family connections.
Well, it could be that Sasuke captures Naruto as part of a plan to protect him from a greater threat that Naruto is unaware of. Maybe Sasuke has some inside information about a powerful enemy who is targeting Naruto, and by 'capturing' him, he can keep Naruto in a safe place until the danger passes.
In the fanfiction, Naruto would be super protective. He'd use his ninja skills to keep the baby safe from any harm. For example, if there was a threat, he could quickly create a barrier around the baby using his chakra. Also, he'd be really patient, which is a bit different from his usual impulsive self when it comes to taking care of the baby.
In this fanfiction, perhaps Gaara wants to show Naruto the unique culture of Suna. They might visit the sand dunes together, and Naruto could be amazed by the different architecture in Suna compared to Konoha.
One possible plotline could be that Naruto gets seriously injured during a mission. Sasuke and Sakura, with their combined skills, take him in and nurse him back to health. They might have to deal with Naruto's stubbornness when it comes to resting and following medical advice. Sakura could use her medical knowledge, while Sasuke could provide protection and also train Naruto in new techniques once he's recovered a bit, strengthening their bond as friends.
One possibility is that the story could focus on the emotional journey of the characters. For example, if Sakura is pregnant, she might be worried about how her friends and the village will react. Naruto could be there to support her, offering his positive energy and friendship. Sasuke might be more reserved in his support but still be there in his own way.
In this fanfiction scenario, their teamwork could reach a new height. Hagoromo would likely train them together, so they would understand each other's strengths and weaknesses better. Naruto's optimism and Sasuke's more brooding nature could be balanced out under Hagoromo's guidance. They might also learn new joint - attack techniques. For example, they could combine Naruto's Rasengan and Sasuke's Chidori in a way that is more powerful and versatile than before. Their bond as friends and comrades would be strengthened, and they would be better equipped to face any future threats to the ninja world.