Naruto might be initially confused. He trusts Tsunade, so being kidnapped by her would be completely unexpected. He would probably start by asking her why she's doing this.
He could be angry. Naruto has a strong sense of freedom and being taken against his will, even by Tsunade, would likely make him mad. He might try to break free and fight back, thinking there's been some sort of misunderstanding or that Tsunade has been tricked.
Naruto could also become angry. He might feel betrayed by Tsunade and the village. This anger could fuel his determination to prove his innocence or worth. He could set out on a journey to become even stronger, so that one day he could return and show everyone that they were wrong to banish him. He might also start to question his own beliefs and values, which have been centered around the village and its people.
She might be initially shocked. Given her own past traumas and her relationship with Naruto, she could be hesitant at first. But then, considering Naruto's lonely situation, she might warm up to the idea and show a more maternal side towards him.
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.
Perhaps in the fanfiction, there is a prophecy or a vision that Tsunade has seen which makes her think that Naruto needs to be in a certain place or situation for the greater good. And she is so desperate to fulfill this that she resorts to kidnapping Naruto. This could lead to a story where Naruto initially resists but then comes to understand Tsunade's reasons as the story progresses.
He could become determined to prove his innocence. Naruto is not one to give up easily. If he was wrongly banished, he would set out on a journey to find evidence or the real culprit to clear his name and return to the village he loves.
She could be angry at first. Tsunade has always been a strong - willed leader, and Naruto leaving without proper communication might seem like a sign of disrespect to her.
Well, in some fanfictions, Tsunade might be devastated. She could go into a state of deep grief and self - blame, thinking she could have done more to prevent Naruto's death. After all, she was his Hokage and had a certain level of responsibility for him.
If Tsunade kisses Naruto, it could strengthen their relationship in a mentor - like way. Naruto might see it as a sign of deep respect and trust from Tsunade. He would likely feel more confident in following her guidance. For Tsunade, it could be a way of showing her pride in Naruto's growth.
Tsunade would probably be very suspicious at first. Naruto suddenly appearing from the future? It's not something that happens every day. She might think it's some kind of enemy's trick or a genjutsu.
Naruto would be angry. He's not the type to just accept being kidnapped. He'd immediately start looking for ways to escape. He might try to use his ninja skills to break free from whatever restraints Orochimaru has put on him.