At first, Naruto might be in shock. He has always trusted his friends, so the sudden betrayal would be a huge blow. He could be silent, unable to process what has just happened.
One possible plot could be that Naruto discovers his friends have been secretly working with an enemy. They might have been promised power or something valuable in return for betraying Naruto. Maybe they spread false rumors about Naruto, turning the village against him.
Naruto would likely become more distrustful at first. He's always been so open and trusting of his friends, so this betrayal would shatter that. He might become more withdrawn, constantly second - guessing people's motives.
Naruto would be devastated. He has always valued his friends highly, and their betrayal would shatter his world. He would likely feel a deep sense of loneliness and confusion. His self - confidence might take a huge hit as he wonders what he did wrong. For example, he might start doubting his own worth and his ability to make good relationships.
In a fanfic, the betrayal might also be a misunderstanding. Her friends could be misled by false information about Sakura. For example, an enemy might spread rumors that Sakura is planning to betray them first, causing her friends to turn against her without really knowing the truth.
Naruto's power might also be affected. If he was betrayed, he could lose the will to fight or train. He might even start to doubt his own purpose. This could lead to a decline in his abilities, which in turn could put the village at risk if he was its main protector.
Sakura could become very angry. She has been let down by those she trusted, and anger is a natural response. She might lash out at her friends or distance herself from them immediately. For example, she could say some harsh words to them in the heat of the moment.
Sometimes, it could be a matter of different loyalties. Naruto's friends might have family or other obligations that conflict with their loyalty to him. For instance, if their families are threatened by someone who demands they betray Naruto, they might feel compelled to do so out of a sense of protecting their loved ones.
It's also possible that her adventure - team friends betray her. In a fictional world, if there are some high - stakes situations like a quest for a powerful artifact, they could betray her for their own gain, such as getting the artifact all for themselves.
In a fanfiction where Naruto is betrayed by his friends, it could start with jealousy. Suppose Naruto gets a great power or a special recognition. His friends, feeling overshadowed, might be tricked by an evil force into thinking Naruto is using them. So they betray him, which makes Naruto realize that he has to rely on his own strength and find new allies who truly understand him.