Sasuke is also a likely candidate. He has always been a brooding and mysterious character. In this fanfic, he could be involved in some sort of secret organization where everything is 'for your eyes only'. He would have to navigate the complex web of secrecy while still dealing with his own personal goals.
It could be Naruto himself. Since he is the main character in the original series, it would make sense for him to be in a fanfic with a 'for your eyes only' concept. Maybe he discovers a secret about his parents that he has to keep to himself for some reason.
Another possibility is Kakashi. He is known for his mysterious past and his many secrets. In the 'for your eyes only naruto fanfic', he could be the keeper of a crucial secret that the whole ninja world depends on. He would have to carefully choose who to trust and how to protect this secret.
Well, it could be about a secret mission in the Naruto world that only a chosen few are aware of. Maybe it involves protecting a powerful and ancient jutsu that must not fall into the wrong hands. Only the most trusted ninjas are entrusted with this mission, and they have to face many challenges along the way.
Sasuke could be the main character in a 'naruto new eyes fanfic'. Imagine Sasuke discovers a new evolution of his Sharingan that gives him additional powers. This could add a new layer to his character arc, as he struggles to come to terms with this new power and how it affects his relationships with Naruto and the rest of the ninja world.
It could be a new character. Maybe an orphan who discovers they have these reanimation eyes and has to figure out how to use them while also dealing with the fact that they are different from everyone else in the ninja world.
It could be an original character created specifically for this fanfiction. Maybe a young ninja who discovers they have these cursed eyes and the power of prophecy unexpectedly.
It could be a jilted lover. Someone who has been betrayed in love and now has angrily eyes, promising pain to the one who broke their heart. This character would be filled with emotions like anger, hurt, and a desire for revenge.
The main antagonists could be a group of rogue male ninjas who oppose Naruto's vision of rebuilding the ninja world. They might believe in a more ruthless and power - hungry approach, seeing the situation as an opportunity to take over. Another possibility is that an ancient evil, sealed away long ago, is released due to the imbalance in the ninja world with only male ninjas alive. This evil entity could be extremely powerful and have motives related to destroying the new order that Naruto is trying to establish.
It could be a group of radical female ninjas who see Naruto as a threat to their new - found power structure. They may want to get rid of him to ensure that the world remains under their complete control.
Temari would also make a great main character. She's tough and has strong leadership qualities. In a female - only world, she could expand the influence of the Sand Village in new ways. She might form alliances with other female - led villages and use her wind - based jutsu to protect her people and the region. Her no - nonsense attitude would be a great asset in this new world.
Naruto himself could be the main character in a Shinju fanfic. He has always been about finding new ways to bring peace and understanding. His connection to the nine - tails could play an interesting role if he were to interact with the Shinju. Maybe he could try to convince the Shinju that the ninja world has changed and it doesn't need to be a source of fear and destruction.
Sasuke Uchiha could be a great choice as the main character. He already has a complex backstory and a lot of room for character development. His journey from seeking revenge to finding his own path in the Naruto series can be further explored in a fanfic.