In a more complex plot, a political conspiracy within the village could be at play. There could be a group that wants to undermine Tsunade's leadership and they manipulate Naruto into believing she is corrupt. They feed him false evidence and use his strong sense of justice against him. Naruto, in his attempt to do what he thinks is right for the village, ends up killing Tsunade, and then has to face the consequences and uncover the real conspiracy.
Maybe a dark force takes over Naruto's mind. This force could be an ancient evil that has been sealed away for centuries and now wants to create chaos in the ninja world. It uses Naruto as a puppet to kill Tsunade, one of the most powerful protectors of the village. The story could then focus on Naruto's friends trying to free him from this control and avenge Tsunade.
Perhaps in this fanfic, Tsunade kills Naruto out of desperation to save the village from a perceived greater threat. If there was a prophecy that Naruto's power would lead to the destruction of Konoha in a certain way, Tsunade, in her role as Hokage, might feel it her duty to stop him at all costs. This would be a very tragic turn as Naruto is seen as a hero in the original story.
If Naruto was adopted by Tsunade in fanfiction, he would probably be exposed to a different set of values. Tsunade is a strong - willed and sometimes reckless woman. Naruto could pick up on her fearless attitude towards battle and also her more practical approach to leadership. Also, their relationship might change the power dynamics in the village a bit, as Naruto would be directly under Tsunade's wing.
One possible plot could be that Tsunade kidnaps Naruto because she believes an enemy is after him and she wants to keep him safe in a secret location. She might think that by taking him away from the village, she can train him without any distractions or threats.
One possible plot could be that Naruto snaps at Tsunade because she refuses to let him take on a dangerous mission. Naruto, being headstrong, believes he is ready but Tsunade, thinking of his safety, says no. This angers Naruto and he snaps, leading to a rift between them until they eventually come to understand each other's perspectives.
The plot could involve a mystery in the village. Strange things start happening, and Naruto, Sakura, and Tsunade have to work together to solve it. Along the way, they face various challenges, and their individual skills and teamwork are put to the test. They also learn more about each other's pasts and how it relates to the current mystery.
One possible plot could be that Naruto and Tsunade are on a dangerous mission together. During this mission, they face many challenges that force them to rely on each other deeply. This shared experience gradually makes them develop feelings for one another. For example, Naruto might be injured and Tsunade uses her medical skills to save him, which makes Naruto see her in a new light, not just as the Hokage but as a woman he could love.
Well, it could be about Naruto accidentally breaking something precious of Tsunade's, like a family heirloom. This might lead to a series of events where Tsunade is initially angry but then Naruto makes it up to her in some heroic way, perhaps by going on a difficult mission for her.
In this type of fanfiction, perhaps Naruto is exiled due to some false accusations. Maybe there's a misunderstanding about his power or some events he's involved in are misconstrued. Tsunade, as the Hokage, might feel pressured by the village elders or some political situation to exile Naruto.
Well, it could be about Naruto having to deal with the unique situation of being Tsunade's son. Maybe he'd inherit some of her strong - willed nature. He might also face different expectations from the village.
Perhaps in the fanfiction, it's a plot device to show a different side of Tsunade. She might be under the influence of a strange jutsu that makes her act out of character and kiss Naruto. This could then lead to a comical chain of events as Naruto tries to figure out what's wrong with Tsunade and the other characters react to this unexpected display of affection. The fanfiction could then focus on how Naruto has to deal with this new situation and keep it a secret from some of the more conservative characters in the village.