Another reason might be related to the events that unfold after the rejection. For example, Naruto might go on to do extraordinary things and form closer bonds with other characters. Sakura could feel left out or jealous, which then leads to her regret. Also, she might have some self - realization about her own feelings at the time of rejection, thinking that she was influenced by wrong factors like social status or her own naivete.
One possible reason could be that Sakura realizes she has different goals or values that are not compatible with being around Naruto. Maybe she discovers a new path in life that doesn't involve him, such as focusing on her own medical ninja career without Naruto's chaotic lifestyle interfering.
One reason could be the realisation of the strong bond they could have had. Kushina might understand in the fanfiction that Naruto has been through so much alone, and she missed out on being there for him. She may regret not being able to protect him from the hardships and bullying he faced as a child.
Perhaps there was some sort of dark influence at play. In the world of Naruto, there are often dark forces and genjutsu (illusion techniques). It's possible that Naruto was under the influence of a genjutsu that made him see Sakura as a threat, so he punched her in self - defense without realizing it was an illusion.
One possible reason could be that Naruto's character development leads him to focus more on other aspects like his ninja duties or his bond with other friends. As he grows, his priorities shift.
Perhaps it's a training exercise that gets out of hand. In the world of Naruto, intense training often mimics real battles. If they were sparring and emotions ran high, it could turn into a full - fledged fight. Also, Sakura might be trying to prove herself to Naruto, and Naruto, not understanding her intentions, might respond aggressively.
Well, one reason could be that Sakura is often written as being too pushy towards Naruto in fanfiction. He might get tired of her always trying to boss him around or control his actions.
There might be some 'naruto is killed by sakura fanfiction' out there. One possible reason could be to explore a dark and alternative storyline. Maybe in that fanfiction, Sakura has been corrupted or misdirected in some way, perhaps by an evil force that makes her turn on Naruto. Another reason could be to create a high - impact, emotional story where the death of a main character like Naruto at the hands of someone close shakes up the entire Naruto -verse in that fan - created narrative.
One possible reason could be that Kakashi later realizes Naruto's potential. He might see how much Naruto has grown on his own despite being ditched, and feels guilty for not being there to guide him more. Another reason could be that Kakashi starts to understand the importance of Naruto in the overall story or the team's dynamic. Maybe he misses the bond they could have had if he hadn't ditched Naruto.
One possible reason could be a misunderstanding. Maybe Sakura said something that Naruto misinterpreted as being hurtful or dismissive of his feelings. For example, if she made a comment about his abilities in a negative way during a crucial moment, it could lead to him distancing himself.
It could be that Sakura betrays Naruto's trust. For example, if Naruto entrusts Sakura with a very important secret, like something related to his family or his new power he's developing, and Sakura reveals it to their enemies or uses it against Naruto in some way, that would be a huge blow to Naruto and could lead to him crying.