One possible plot could be that Naruto discovers some dark secrets about Konoha's leadership. For example, he might find out that they were involved in unethical experiments in the past. This discovery could make him feel betrayed first, and then lead him to take actions that Konoha sees as betrayal, like refusing to follow orders or even teaming up with an enemy of Konoha who he believes has a more just cause.
Maybe Naruto is framed for a crime he didn't commit in Konoha. The village turns against him quickly without a proper investigation. Feeling angry and hurt, he decides to leave Konoha and in the process, he has to fight against some of his former friends and allies who are trying to capture him. As he defends himself, Konoha views his actions as betrayal.
The Konoha elders could be the main antagonists. They are often shown to be quite traditional and set in their ways in the original series. If Naruto goes against their old - fashioned ideas about the village's future and ninja code, they would likely oppose him strongly and could be the driving force behind making Naruto an outcast, which in turn could lead to his 'betrayal'.
One possible reason could be that Naruto discovers some dark secrets within Konoha. Maybe he finds out that the village elders have been using him all along, not truly caring about his well - being but only his power as a Jinchuriki. This realization could be so shocking that he decides to turn against the village.
One possibility could be a misunderstanding. Maybe Kakashi is framed for something that makes Naruto believe he has betrayed him. For example, an enemy could use a clone of Kakashi to perform a heinous act, and Naruto witnesses it without seeing the full picture.
One possible reason could be power. Maybe in the fanfic, there's a new source of power that Tsunade wants desperately and Naruto stands in her way to obtain it. So she betrays him to get to that power.
The 'naruto returns to konoha fanfic' might focus on Naruto's relationships. For example, his relationship with Sakura could be explored further. He might come back to Konoha and realize his true feelings for her, or there could be some unresolved issues between them that need to be sorted out. Also, his bond with Kakashi and the other villagers would be re - established in a new light, as he has changed during his time away.
One possible plot could be that Naruto is pushed to the edge by the village's mistreatment of him. Maybe they wrongly accuse him of a serious crime, and in his anger and sense of betrayal, he decides to take revenge on Konoha. He could use his powerful jutsu to cause destruction to the village's infrastructure and fight against those who oppose him.
Well, one possible plot could be that Naruto is betrayed by Konoha in some extreme way. Maybe he discovers some dark secrets about the village leadership that involve using him as a tool all along. This betrayal could push him to the edge and make him turn against Konoha, leading to a situation where he kills those who he feels have wronged him.
It could also be that Naruto has a misunderstanding. He might misinterpret some actions of Konoha as being malicious towards him or his friends. As a result, he decides to oppose the village. However, as the story progresses, he realizes his mistake and instead works with Konoha to resolve the issues that led to the misunderstanding in the first place.
It could be about Naruto coming back to Konoha after a long and dangerous mission. Maybe he has new skills and powers to show off.
Another aspect could be related to her past or origin. If she has some hidden memories or a secret agenda tied to her existence as the Fem Kyubii, it could lead her to betray Naruto. For example, if there are some dark forces that are controlling or influencing her from her past, she may be forced to turn against Naruto against her will in a sense.