In a fanfic, Naruto could inherit the Sharingan from a long - lost relative. This relative could be an Uchiha who fell in love with an Uzumaki long ago. With the Sharingan, Naruto gains the ability to predict his opponents' moves more accurately. He uses this new power in combination with his Rasengan to create new and powerful jutsus, and he also has to figure out how to control the Sharingan's curse, which comes with its own set of challenges.
One possible plotline could be Naruto unlocking the Mangekyo Sharingan through some strange and unforeseen means, perhaps a powerful jutsu backfires and gives him this new power. Then he has to struggle with controlling it while his friends are both amazed and a bit worried about this new development in him.
One interesting storyline could be Naruto discovers he has Sharingan after a strange encounter with an ancient Uchiha artifact. This new power makes his enemies question his identity and alliances, and he has to struggle with the newfound power while still being true to his ninja way.
Another plot idea is that Naruto gets a Sharingan in a parallel universe. In this universe, he has to learn how to control it quickly while also dealing with the different political situations. Since the Sharingan is so powerful, many might try to either use Naruto or take the Sharingan from him, creating a lot of action - packed and suspenseful situations.
One interesting plotline could be Naruto struggling to control the power of the curse mark. It might lead him to make some unexpected decisions. For example, he could be tempted to use the dark power in the curse mark to defeat a powerful enemy quickly, but at the risk of losing himself to the darkness. Another plotline could involve Naruto trying to find a way to remove the curse mark without anyone's help, showing his independent and determined side. Maybe he goes on a journey to find a rare herb or a hidden technique that can get rid of it.
Another plot could be that the Sharingan is given to Naruto as a last - ditch effort to save the village. A dying Uchiha gives Naruto his Sharingan, and Naruto has to figure out how to incorporate it into his already powerful set of skills. He might have to deal with the jealousy or suspicion of some of his comrades who are wary of the Sharingan's power.
One possible plotline could be the main character having a unique form of the Sharingan that gives them powers beyond what is normal in the Naruto universe, like the ability to time - travel. This could lead to them changing the course of major events in the Naruto story.
One possible plotline could be Naruto suddenly gaining the Sharingan through some mysterious jutsu accident. With the Sharingan, he could quickly learn new techniques and have enhanced perception. Combined with the Kyuubi's power, he might become an almost unbeatable force. For example, he could use the Sharingan to better control the Kyuubi's chakra flow, making his attacks more precise and powerful.
Yes, there are likely fanfics out there where Naruto has one Sharingan. Fanfic writers often come up with creative and alternative storylines, and this could be one of them. They might explore how Naruto got the Sharingan, what new abilities he could gain from it, and how it would change his relationships with other characters in the Naruto universe.
One interesting fanfic could be 'Naruto: The Dual - Eyed Avenger'. In this fic, Naruto's acquisition of the Rinnegan and Sharingan completely changes the power dynamics in the Naruto universe. His new abilities make him a force to be reckoned with, and he uses them to protect Konoha in ways no one expected.
One possible plotline could be Naruto forming a unique bond with Chomei. Maybe Chomei helps Naruto in a difficult battle by using its special abilities, like its ability to manipulate the nano - sized insects. This could give Naruto an edge against a powerful enemy.