Of course, some original Uchiha characters like Mikoto Uchiha. She was Itachi and Sasuke's mother. In a time - travel fanfiction, Naruto could interact with her in a way that changes the course of history. Maybe he saves her life, and she feels indebted to him, leading to her being part of his harem. Her motherly instincts could also be a factor in how she interacts with Naruto and the other members of the harem.
Another plot could involve time travel as a means of fixing the Uchiha massacre. In this fanfiction, Naruto travels back and his harem, which consists of Uchiha members, helps him in this mission. They use their unique Uchiha abilities and their bond with Naruto to try and prevent the tragedy. This can lead to a lot of emotional and action - filled scenes as they face off against those who want the massacre to happen.
One possible plot could be that Naruto travels back in time and meets Mikoto Uchiha. He might try to prevent the Uchiha massacre. Since Naruto has knowledge of future events, he could use this to his advantage. He could also form an unlikely alliance with Mikoto, who was an important figure in the Uchiha clan. This could lead to a whole new timeline where the Uchiha clan doesn't face destruction and Sasuke has a different upbringing.
Obviously, Kushina herself would be a central character. Minato could also be involved, perhaps in a complex relationship triangle with Naruto and Kushina. Then there are other female ninjas like Tsunade. She might be intrigued by Naruto's time - traveling knowledge and get involved in the story. Sakura could also be a potential character. If she somehow gets dragged into the time travel, she might have her own role in the harem - like situation around Naruto.
In such a fanfiction, Princess Bubblegum from Adventure Time could be in the harem. She's intelligent and powerful, and Naruto's unique skills and personality might attract her. Also, Sakura from Naruto could be part of it. Since she has a history with Naruto and in this crossover, she could be part of the group vying for his attention. And Marceline too. Her cool and edgy nature might be drawn to Naruto's heroic side.
Well, there's a fanfiction where Naruto travels back and meets Itachi as a young Uchiha. Naruto tries to understand Itachi's motives better and in the process, he gets involved in the internal Uchiha affairs. It's a great read as it shows a different side of Itachi and how Naruto's presence could have changed things. Also, 'Naruto's Time - Jump to the Uchiha Era' is a fanfic that focuses on Naruto learning about the Uchiha's unique abilities and culture during his time - travel adventure.
Perhaps Naruto travels back in time to a crucial moment in Anko's life, like when she was involved with Orochimaru. He uses his future knowledge and Uchiha powers to try and prevent her from getting too deeply involved with Orochimaru. Along the way, they develop a bond that was not present in the original timeline. As they interact more, they start to change the future in unexpected ways, not just for Anko but for the whole ninja world. Their relationship could be a mix of friendship, mentorship, and perhaps something more romantic as they face various challenges together in this altered timeline.
It could be Sasuke's sister, if there was one in the fanfiction world. She might share some of Sasuke's traits but also have her own unique personality that attracts Naruto.
Definitely Sasuke. Their relationship has always been complex and full of unspoken feelings. Naruto is also a strong contender as he has always cared for Sakura deeply. Rock Lee might be in the harem too. His admiration for Sakura has been quite obvious throughout the series. And perhaps Kiba, who could see Sakura in a new light during the time - travel events. Also, an older or more experienced version of a minor character from a different clan might be attracted to Sakura's growing power.
Boruto could be an unexpected ally. Maybe he somehow gets caught up in the time - travel event with Sarada. They have a strong bond in their own time, and that would carry over. They could work together to face the challenges of the different time periods, like when they encounter powerful and dangerous ninjas from the past or future.
One great Naruto Uchiha and Mikoto time travel fanfiction is 'A New Chance'. In it, Naruto travels back in time and teams up with Mikoto. The story has really interesting character interactions, especially between Naruto and the Uchiha clan. It shows how Naruto's modern - day knowledge can change things in the past. Another good one is 'Time - Twisted Bonds' where Mikoto and Naruto's time - travel adventure leads to unexpected alliances within the Uchiha clan, and they work together to prevent future tragedies.