One possible plot could be that Naruto witnesses the death of a fellow ninja from his village during a battle. Maybe it's someone he has trained with or has a friendly rivalry. This would cause him to cry as he feels a deep sense of loss for his comrade and also blames himself for not being able to protect them.
Perhaps Naruto sees the death of an innocent civilian. In the Naruto world, civilians often get caught in the crossfire of ninja battles. This would shatter Naruto's view of protecting the village as a whole. He'd cry because he realizes that his efforts to bring peace haven't been enough to safeguard the most vulnerable. It could lead him to question his path and seek a stronger way to protect everyone.
It might be Iruka - sensei. Iruka was one of the first people to recognize Naruto for who he was and give him a sense of belonging. If Iruka were to die, Naruto would remember all those early days of support and kindness. His death would break Naruto's heart as it would be like losing a part of his family, the family that accepted him when no one else did.
It could be a random civilian. This would show Naruto the impact of the ninja world's violence on ordinary people, making him more determined to protect the innocent.
The aftermath could be Minato's quest for revenge if Naruto's death was caused by someone. He would use his skills and knowledge to track down those responsible. Or, he could be plunged into a deep depression. He might isolate himself from the other spirits or entities in the afterlife. His whole existence could become centered around his grief and his memories of Naruto.
This event can be a huge turning point for Naruto. It might make him more determined to protect others. He could become more serious about his training and his goal of bringing peace to the ninja world. Seeing the death might also make him more empathetic towards those who have lost loved ones.
One possible plot could be that Hinata accidentally stumbles upon Naruto's memories during a mission. Maybe they are in a strange place where memories are made visible, and Hinata starts to understand Naruto on a much deeper level. She sees his lonely childhood, his determination to be recognized, and his dreams for the future. This newfound understanding could strengthen their relationship and make Hinata more determined to support Naruto in his goals.
Well, one possibility could be that Naruto has some sort of visionary ability where he can see snippets of the future during his past adventures. For example, he might see the final battle against Kaguya while he's still on a mission with his team as a genin. This could change his approach to training and how he interacts with his friends, as he tries to prepare them for what's to come.
Another interesting plot twist could be related to the purpose of Naruto's transformation. Suppose Naruto transforms to save Sakura from a dangerous situation. But the transformation has some unforeseen side effects. For instance, he might lose control of his new powers temporarily. Sakura then has to find a way to help him regain control while also dealing with the threat that made him transform in the first place.
The plot might involve Naruto crying due to a misunderstanding with his friends. Kakashi witnesses this and steps in to mediate. He first calms Naruto down and then arranges for Naruto and his friends to have an open conversation. During this process, Kakashi shares some wisdom about friendship and communication, helping them resolve their differences.
Maybe in the fanfic, Naruto sees a future where Konoha is destroyed. This makes him determined to change the future. He could start by strengthening the village's defenses, forging new alliances, and also trying to figure out the root cause of the destruction in the future he saw. He might also try to uncover any hidden threats within the village that could lead to such a catastrophe.
One possible plot reason could be for Naruto to experience a great loss that changes his character completely. Maybe it's part of a dark plot where the enemy is so powerful that they manage to kill Hinata right in front of Naruto. This would fuel his rage and determination to become even stronger and seek revenge. Another reason could be related to some sort of sacrifice. Hinata might sacrifice herself to save Naruto or someone else important, and Naruto has to deal with the guilt and grief of her death.