A great way to develop the plot is to think about how the world of 'Naruto' would react to the role reversals. If Naruto was born with great natural talent like Sasuke in the original, how would the other characters treat him? Would there be more jealousy or admiration? And how would this affect the overarching story of the ninja world, like the Akatsuki's plans or the relationships between different ninja villages? It could lead to a very complex and interesting plot.
To develop the plot in a roles reversed 'Naruto' fanfic, consider the backstories. If the roles are reversed, the events that led to the characters' current states would be different. Maybe Naruto's family was killed by a different enemy, and that's what drives his new personality. This new backstory can then be used to build up the plot, with new mysteries and revelations along the way. For example, Naruto might be on a quest to find out who really killed his family, and this journey could be filled with many twists and turns as he uncovers secrets about the ninja world.
The plot could start with the reversed personalities or situations of the main characters. For instance, if Naruto is the cool and collected one while Sasuke is the hot - headed. Then, their goals might change. Naruto could be more focused on revenge or something dark, and Sasuke on bringing Naruto back to the light. This would create a whole new set of conflicts.
One possible plot could be that Sasuke, in the reversed role, is now the one trying to gain the village's recognition. He might be the underdog with a big dream, like Naruto originally was. He could be using his Sharingan in new ways to protect the village and its people, while Naruto, in Sasuke's role, has a more brooding and solitary nature, perhaps having left the village due to some past event and Sasuke is now on a journey to bring him back.
One interesting concept could be the reversal of the power dynamics. For example, if Naruto was initially a villain or a very shy and introverted character instead of his usual energetic self. It would completely change the story's progression and his relationships with other characters like Sasuke and Sakura.
A great plot could be that Sasuke, in the reversed role, is the village's hope. He is the one everyone looks up to. Naruto, with a dark past that led him to be bitter, is on a path of self - destruction. Sasuke tries to stop Naruto from causing harm to himself and others. He uses his own positive energy and the power of friendship to make Naruto realize that there is more to life than revenge. This would be a complete role reversal from the original Naruto and Sasuke dynamic.
One idea could be that Sasuke, in the role of the underdog, is constantly trying to prove himself in the village. He might be the one with a big heart, always reaching out to others. Meanwhile, Naruto could be the brooding loner who has a natural talent but is haunted by his past. For example, Sasuke could be the one to develop a new jutsu to protect the village, while Naruto is off on his own journey, slowly coming to terms with his need for connection.
The plot could start with Naruto accidentally stumbling upon the EMS. Then, as he tries to figure out how to use it, he attracts the attention of various ninja clans who either want to steal it or help him. This creates a lot of conflict and action.
It adds diversity to the existing stories. By changing the gender roles, it gives a fresh perspective on the familiar characters and settings. Fans can explore different dynamics and relationships that might not have been as prominent in the original work.
In a 'Star Trek' reversed gender roles fanfic, the female characters could be the captains and lead the exploration missions, while the male characters serve as the ship's doctors or engineers. There are also fanfics in the 'Lord of the Rings' universe where female hobbits or elves are the ones on the grand adventures, taking the place of the male characters in the original story.
Perhaps in this fanfic, Astrid is the one with the mysterious past involving dragons. She has to hide her knowledge and connection to them from the rest of the village. Hiccup, being the popular and more 'normal' Viking, starts to suspect something about Astrid and eventually uncovers her secret, leading to a change in their relationship and the village's view of dragons.
A 'Naruto and Gaara Roles Reversed' fanfiction could start with Gaara being the one full of energy and constantly getting into trouble in the Leaf Village. He'd be eager to prove himself, much like how Naruto was in the original. Naruto from Suna would have to deal with the harsh treatment from his own village due to being the Jinchuriki. Their first encounter would be really interesting, as their personalities and circumstances are flipped.
The plot could start with Naruto encountering a strange entity that bestows the One for All power upon him. He then has to keep it a secret while he figures out how to use it. As he progresses, he discovers that there are others who are after this power, which leads to a series of battles and chases.