One possible reason could be that in the fanfic, Jiraiya might have made a decision that Naruto strongly disagreed with, like leaving him alone at a crucial time for a long mission. This could make Naruto feel abandoned and thus start to hate him.
One possible reason could be that in this fanfic's unique plot, Jiraiya might have made a decision that Naruto strongly disagreed with. For example, Jiraiya could have been involved in some political intrigue within the ninja world that Naruto thought was against his ideals of justice and peace.
Well, it would probably make Naruto's relationship with Tsunade more strained. Since Tsunade was close to Jiraiya, Naruto's hatred for him might make Tsunade view Naruto in a different light, and Naruto might also be less trusting of her. For example, Naruto might avoid going to Tsunade for help as he used to.
Well, it would surely affect Naruto's relationship with Tsunade. Since Tsunade was close to Jiraiya, Naruto's hatred for Jiraiya might make him more distant from Tsunade. He may not trust her as much as he did before because of her connection to Jiraiya.
One possible reason could be that Naruto feels he has learned all he can from Jiraiya at that point. Maybe he wants to explore his own path independently and test his skills without Jiraiya's constant guidance.
In the original storyline, Naruto had a deep respect and love for Jiraiya. Jiraiya was like a father figure to him, training him and imparting important life lessons. Tsunade also cared for Naruto and was an important figure in the village. In the fanfiction where Naruto hates them, it completely flips this dynamic, which is a major deviation.
One possible reason could be a misunderstanding. Maybe Naruto overheard some false information about Jiraiya and Tsunade that made him think they had wronged him or someone he cared about. For example, if he heard they were involved in a plot that led to the death of a fellow villager, it could turn his feelings sour.
Perhaps Naruto blames them for some of the hardships he faced. Maybe he thinks that Jiraiya wasn't around enough when he needed a mentor, and Tsunade didn't do enough to support him in certain situations. This could lead to feelings of resentment and hatred in the context of the fanfiction.
In the original story, Naruto respects and looks up to Jiraiya as his mentor. He also has a good relationship with Tsunade. But in this fanfiction, the hatred is a complete departure. It changes the whole dynamic of their interactions.
A fanfic like this might explore how fem Naruto's presence affects Jiraiya's typical behavior. Jiraiya is known for his pervy tendencies in the original series, but with a fem Naruto, he might have to control himself more. It could also be about how fem Naruto looks up to Jiraiya as a strong ninja and a source of wisdom, and how she tries to learn from him to become a great kunoichi.