Well, Naruto is a kind - hearted person. When he realizes Sakura thinks he's her boyfriend, he could try to go along with it for a while to see where it leads. He might start to notice things about Sakura that he hadn't before, like how she really cares for him in a different way. As time goes on, he could either grow to have real romantic feelings for her or gently let her down if he realizes it's not what he wants. He would also be worried about how this would affect their friendship and the dynamics within their team.
Naruto might initially think it's a joke. He's used to Sakura being a bit unpredictable, but when he realizes she's serious, he could feel a bit pressured. He doesn't want to hurt her feelings, but he also doesn't want to lead her on. So he might try to avoid her for a while until he figures out how to handle the situation. He might also talk to his other friends, like Shikamaru, for advice on how to deal with Sakura's newfound belief.
One possibility is that Naruto is initially confused by Sakura's assumption. He might be so focused on his goals, like becoming Hokage, that he hasn't really considered a romantic relationship with Sakura in that way. He could gently let her down, explaining that he values her as a friend and teammate but doesn't have those romantic feelings. This could lead to a bit of an awkward phase in their relationship, but they would likely work through it and return to their strong friendship.
She might be confused at first. Sakura is used to Naruto being friendly and always there for her, so his coldness would be unexpected. She may start to question what she has done wrong.
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.
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.
Sakura might be initially confused. She could be thinking about what she did wrong to make Naruto stop talking to her. Since they have been friends for a long time, this sudden change would be very puzzling for her.
Sakura might also get angry. She could feel that Naruto is being unfair or cowardly. She might try to find Naruto and confront him about why he left her alone. In the process, she could end up growing stronger both physically and emotionally. For example, she might train harder to prove to Naruto that she doesn't need him around. And also, she could start to re - evaluate her own feelings and relationships in general.
She might be initially shocked. After all, Naruto has always been a friend, and this sudden display of such an intimate gesture could catch her off - guard. But then she could feel a warm feeling spreading through her, a sense of being cared for deeply.
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.