One possibility for such a fanfic is that Naruto has been through some kind of trauma that makes him view Sasuke and Sakura differently. For example, if Naruto was betrayed by someone he trusted deeply who had similarities to Sasuke and Sakura in some aspects. It could change his perception of them completely and fuel his hatred in the fanfic.
In such a fanfic, one possible reason could be Naruto's feeling of being left out. Maybe he sees Sakura's constant focus on Sasuke and feels neglected in their friendship triangle. Another reason might be jealousy. If Naruto has unrequited feelings for Sakura, seeing her love for Sasuke could turn to hatred over time.
The relationship would become very tense. Naruto would likely avoid Sakura and Sasuke. There would be no more of the friendly banter or the complex emotional triangle that was there before. It's a complete shift from their normal relationships in the original story.
Maybe in the fanfic, Sasuke has done something to betray Sakura's trust. For example, he might have left the village again without considering her feelings.
The original story focuses on Naruto and Sasuke's relationship as well as Sakura's love for Sasuke as a driving force for her growth. But the fanfic where Sakura hates Sasuke takes a different turn, it might focus on different aspects of Sakura's character, like her independence and self - realization without the influence of her love for Sasuke.
A scenario could be that Sasuke blames Sakura for something that went wrong in his revenge plan. Maybe she unknowingly did something that set him back, and in his anger and single - minded focus on revenge, he starts to hate her. Another possibility is that in the fanfic world, there is a misunderstanding. Sakura is misinterpreted as being involved with someone who has wronged Sasuke, and this causes him to hate her without really knowing the truth.
In proper fanfics rather than 'lemon' ones (as 'lemon' implies inappropriate content), Naruto is known for his never - give - up attitude. He's the heart of the story, always trying to bring Sasuke back and protect his friends. Sasuke is a complex character, with his family's past haunting him, which makes him seek power and revenge at times. Sakura, she starts as a girl with a crush but evolves into a capable ninja. These characteristics are often the foundation for fanfic authors to create interesting stories that don't involve improper content.
One possible reason could be jealousy. Maybe in the fanfiction, Naruto feels overshadowed by Sasuke in Sakura's eyes, which leads to his hatred. Another reason might be that he perceives their relationship as a threat to his own bonds with them. For example, he could think that Sasuke and Sakura's closeness excludes him in some way.
Often in these fanfics, Sakura might make fun of Naruto's dreams or goals in a very mean - spirited way. This constant put - down could lead Naruto to hate her. Also, if Sakura were to side with Naruto's enemies in the fanfic for some reason, like being brainwashed or having a hidden agenda, it would be a likely cause for Naruto's hatred.
Well, one possible reason could be that Sasuke's mistake might have put their team in great danger. For example, if his actions led to the enemy getting an upper hand during a battle, endangering not only his life but also those of his comrades like Sakura. Sakura, who values the safety of the team, would then resent Sasuke for his mistake.