One possible plotline could be that Naruto accidentally travels back in time and lands right in front of Tsunade when she was at a crucial point in her life, like just after the death of her loved ones. Naruto, with his future knowledge, helps her cope and in the process, they grow closer. Another plotline could be that Tsunade is sent to the future where she meets an older and more mature Naruto. They initially clash due to their different outlooks from different times but then gradually fall in love as they understand each other better.
One plotline could be about Hinata and Tsunade helping Naruto in his diplomatic missions. Hinata with her gentle nature could be good at building relationships with other villages, and Tsunade with her experience and leadership could guide Naruto in making tough decisions.
One possible plotline could be that they go back in time to prevent a major disaster that happened in their own time. For example, they might try to stop the destruction of the village. Another could be that they are sent back to change the course of their own relationship. Maybe in their original timeline, they had some misunderstandings, and going back gives them a chance to fix things. It could also be that they are sent back to learn something specific, like a long - lost ninja technique that only existed in the past.
One possible plotline could be that Naruto discovers a new form of chakra control that gives him an edge over Tsunade. He uses this to take charge in a dangerous mission where Tsunade was initially leading.
Maybe Naruto travels back in time to a point where Anko is in a difficult situation. He uses his sharinnegan abilities to help her out, and during this process, they start to develop feelings for each other that were not present in the original timeline. And as they try to return to their own time, they face various challenges that test their relationship and their new - found powers.
Perhaps they time - travel to a time when the ninja world was at peace. Naruto, who is used to a world full of conflict, is initially out of place. Mikoto helps him adjust. They start to fall in love during their adventures in this idyllic past. They might discover secrets about the origins of certain jutsus or ninja clans that were lost in Naruto's time. Their relationship could be a source of both strength and confusion as they navigate a world that is both familiar and strange to them.
Well, if there is such a fanfiction, perhaps there's a plot where some sort of magic or jutsu affects their minds. Naruto might be under a spell that makes him see Tsunade in a romantic way, and Tsunade, being affected by a similar or related jutsu, reciprocates. And so, in this strange situation, they end up in a situation where they'sleep together'. But this is all just speculation based on what could be in a very unorthodox fanfiction.
In a time - travel scenario, Naruto could go back in time and meet a younger Tsunade. His knowledge of her future self might make him initially approach her with a sense of familiarity. Tsunade, on the other hand, would be intrigued by this strange boy. Their relationship could start as a friendship, with Naruto gradually showing Tsunade a different perspective on life and ninja values. As time passes, they might start to develop deeper feelings for each other, based on mutual understanding and shared experiences in this altered timeline.
Another plotline might be that Tsunade is affected by some kind of dark magic or genjutsu that makes her turn against Naruto. Naruto, realizing it's not really Tsunade's fault, still has to fight her to try and break the spell. He could call upon his friends for help, but in the end, it's his determination and his bond with Tsunade that helps him reach her and break the control.
One possible plotline could be that Naruto leaves with Tsunade on a mission to find a rare herb that is said to have the power to heal any wound. Along the way, they face various enemies who also want the herb for their own malicious purposes. Naruto's skills and Tsunade's wisdom would be put to the test as they battle their way through.
A possible plotline could be a training arc. Tsunade could be training both Naruto and Sakura in a new and advanced form of combat or medical ninjutsu. This would involve a lot of character development as they struggle to master the new skills. For example, Naruto might have trouble with the precision required in a medical - related technique while Sakura helps him out, and Tsunade observes and gives tough love guidance.