One possible reason could be if Sakura constantly criticizes Naruto's abilities in a very harsh way. In the story, Naruto has always been striving to prove himself, and if Sakura doesn't show any faith in him, it might make him angry.
It could also be that Sakura makes decisions without considering Naruto's feelings or opinions. For example, if she gets involved in a dangerous mission without consulting him and puts herself at risk, Naruto, who cares about her deeply, would likely be angry. He values her safety and their friendship, and such actions could be seen as disrespectful to their bond.
In some fanfictions, Sakura might accidentally hurt Naruto during a training session. Maybe she uses a new jutsu she's not fully mastered and it goes wrong, hitting Naruto instead of the target.
Perhaps in the fanfiction world, Naruto has other relationships or commitments that make him avoid Sakura. For example, he could have made new friends or allies who don't get along well with Sakura, so to keep the peace or not get involved in drama, he stays away from her.
In fanfiction, Naruto could hate Sakura due to her treatment of him. She often overlooked his feelings in the original series. Fanfic authors might exaggerate this aspect. For example, if Sakura continuously dismisses Naruto's achievements or makes him feel inferior, it can build up to a strong dislike or hatred in the fan - created stories. Also, some fanfictions might explore a darker side of Naruto where his pent - up emotions turn into hatred for Sakura, perhaps as a way to show his growth into a more complex character with a wider range of emotions than just the positive ones shown in the original anime.
Another reason could be that she values the authenticity of the original Naruto narrative. Fanfictions are often the product of fans' wild imaginations and might not align with the official story. She might be a purist when it comes to the Naruto story she is a part of, and thus hates fanfiction that strays too far from the original.
The fanfiction might change the important events in his life in a way that he doesn't like. For example, if it rewrites how he became a ninja or his relationship with his teacher, Iruka. These are fundamental parts of his story, and if they're distorted in the fanfiction, it's understandable that he'd get angry.
Another reason could be in a fan - created scenario where there are secrets involved. Hinata might be keeping a secret from Naruto that, when revealed, makes Naruto feel betrayed or deceived. This sense of betrayal could easily turn into anger. For instance, if Hinata has a connection to an enemy that she's been hiding from Naruto.
Yes, in some fanfictions, Sakura can get jealous of Hinata. For example, if Hinata has a closer relationship with Naruto than Sakura does in the story, Sakura's feelings for Naruto might make her jealous. It could be because Hinata is always so supportive and kind towards Naruto, which Sakura may feel she lacks in comparison.
Well, in fanfiction, Sakura might use her intelligence and understanding of both Naruto and Hinata to bring them together. She could notice the little things, like how Hinata blushes around Naruto and how Naruto unconsciously looks for Hinata in a crowd. Sakura could then subtly plant ideas in their heads. For instance, she might mention to Naruto how Hinata is always there for him when he's in trouble. And to Hinata, she could say how Naruto really values her presence. This way, she gradually builds a connection between them until they realize their feelings for each other.
Sakura could also try to stand up for herself. If she believes that Sasuke is being unfair in his anger, she may argue back. For instance, if Sasuke is angry because of a misunderstanding, Sakura might try to clarify the situation and prove her point.
In fanfiction, sometimes the writers have their own interpretations. They could see Naruto's character in a way where his goals and dreams, like becoming Hokage, are so all - consuming that he simply doesn't have the emotional space to care about Sakura. His attention is diverted to more important things in his mind, such as protecting the village and his friends in a more general sense rather than having a special care for Sakura.