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.
One possible plotline could be Naruto feeling extremely lost and having to find his own way to become stronger without their guidance. He might start to question his own worth and abilities, but then he could meet new allies who help him realize his true potential on his own. For example, he could encounter some other outcast ninja who have their own unique skills and together they form a new kind of ninja team that challenges the traditional ways of the ninja world.
One possible plotline could be Naruto growing up with a different set of skills influenced by Tsunade. Since Tsunade is known for her medical ninjutsu and super strength, Naruto might have an earlier inclination towards medical skills. He could be trained in a more balanced way between combat and healing. For example, in battles, he not only uses his regular jutsu but also heals his comrades instantly on the spot. Another aspect could be the political influence. Tsunade being an important figure in the village, Naruto might have a different standing in the village hierarchy from the start and face different kinds of challenges related to leadership and decision - making.
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.
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.
A plotline could revolve around Sakura trying to understand Tsunade's past more deeply. Tsunade might be reluctant at first, but as they work together more closely, she starts to open up. This could lead to Sakura learning important life lessons from Tsunade's experiences, like how to deal with loss and keep going. They could also get into a situation where they have to use their combined medical and combat skills to save a group of injured ninjas.
One possible plotline could be that Luke has been corrupted by some dark force, and Percy has to fight him to save their world. Percy might be reluctant at first because they were once friends, but the greater good forces him into action.
One possible plotline could be that Tsunade and Naruto go on a dangerous mission together and Tsunade has to protect Naruto at first, but then Naruto's growth allows him to contribute significantly. Another could be that Tsunade is teaching Naruto some special medical jutsu, and they have a mentor - mentee relationship throughout the story.
One plotline could be about Naruto helping Tsunade to further reform the Hidden Leaf Village. Since Naruto is now married to Tsunade, he has more influence and they work together to improve the village's economy, ninja training systems etc. Another could be that they face opposition from some traditionalist shinobi who don't approve of their age - gap relationship.
One possible reason could be a misunderstanding. Maybe Tsunade received some false information about Naruto that made her think he was a threat to the village, so she took actions that ended up hurting him.