On the other hand, Naruto could also be understanding. If he realizes that Sakura has her reasons, even if they are wrong, he might try to forgive her. Naruto has always been one to see the good in people, and he might hope that they can work through whatever has caused this situation. He may try to talk to her calmly to resolve the issue, showing his maturity and his belief in their friendship.
Naruto might initially be shocked and heartbroken. He may try to hide his pain and put on a brave face, as he has always done in the face of adversity. He could also become withdrawn for a while, distancing himself from Sakura as a form of self - protection.
One possible reason could be a misunderstanding. Maybe Sakura misinterprets Naruto's actions or words, thinking he has betrayed her or their friends in some way, which leads to her hurting him one last time in a fit of anger.
At first, Naruto might be extremely shocked. He has always seen Tsunade as a respected figure. So when she hurts him, he may not be able to immediately process it. He could be speechless and just stare at her in disbelief.
Naruto might be very forgiving right away. He has always had a big heart and cared deeply for Sakura, so he could just accept the apology with a big grin and say it's all in the past.
Naruto could also feel a deep sense of hurt. After all, he has been through a lot with Sakura. In the face of her betrayal, he might start to question his own judgment of people. However, being Naruto, he would not give up easily. He might try to find a way to redeem Sakura or at least make her see the error of her ways. He would draw on his own experiences of being ostracized in the past and use that to try to understand her actions and find a solution.
Naruto might initially be shocked. Given his friendly nature towards Sasuke in the original story, he wouldn't expect such an attack from her. So, his first reaction could be pure disbelief.
She might be heartbroken. Sakura could initially be in shock and then fall into a deep sadness. She may blame herself for Naruto's leaving, thinking that she could have done something differently.
At first, Naruto might be extremely shocked. He trusts Sakura as a teammate and friend, so being kidnapped by her would be completely unexpected. He would likely try to talk to her, asking her why she's doing this.
He may try to talk to Sakura and understand her reasons. Naruto is a character who believes in the goodness of people. So, instead of getting angry immediately, he would likely want to resolve the issue. He could also become determined to prove himself to Sakura, that whatever she thinks he has done wrong, he is actually not that person.
However, in other cases, Naruto could be hesitant. He might have grown so used to their friendship that the idea of a romantic relationship with Sakura is a bit overwhelming. He could take a step back and say something like 'Sakura, this is really unexpected. I need some time to think about this.' This would then lead to a more complex exploration of their relationship in the fanfiction.