Naruto would likely be curious. He'd want to know all about how this female version of himself came to be. He might start asking questions about her life, her training, and her relationships. He could also compare her abilities to his own and might be impressed by some of the things she can do that he can't or vice versa. He'd probably try to find common ground between them and bond over their shared ninja heritage.
He'd probably be super surprised. I mean, seeing yourself as the opposite sex is not something that happens every day. He might blurt out something like 'Who are you? You look like me!' and then start to realize the situation. He could be a bit embarrassed too, especially if female Naruto had some different mannerisms or ways of dressing.
Naruto would probably be very curious. He's always open to new things and new people. He'd likely ask her a ton of questions about where she's from and what she can do.
Naruto would definitely fight back. Despite being kidnapped, she has a strong will and a lot of chakra. She would use her Shadow Clone Jutsu to create distractions and try to break free from her captors. And she would also be yelling at them, trying to get them to see the error of their ways.
Well, one possibility is that Naruto might be really confused at first. He'd see this different version of himself as a female and might not immediately understand the situation. He could try to figure out how this time - travel happened and what it means for his world. Maybe he'd start to learn about the differences in how female Naruto is treated in this new world compared to his own experience as a male.
Naruto would probably be initially shocked and on guard. He's used to all kinds of strange things in his world, but a Fem Predator would be something entirely new. He might try to talk to her first, asking who she is and what she wants. If she showed any signs of aggression, he'd be ready to fight, using his Rasengan or other jutsu. But if she seemed peaceful, Naruto would be curious and want to learn more about her, maybe even offer her some ramen to break the ice.
He might be initially confused. Naruto is used to dealing with all kinds of opponents and situations, but a yandere Kyuubi would be a new and strange thing for him. He could try to reason with her at first.
At first, Naruto would be completely shocked. He has always seen Hinata as a loyal friend and someone who has deep feelings for him. So the idea of her betrayal would be hard to fathom. He might try to deny it at first.
He would be filled with rage. Naruto has a strong sense of justice and the fact that someone took Hinata away from him would fuel his anger. He would vow to find and punish whoever was responsible. He might even become reckless in his pursuit of vengeance, endangering himself and those around him. His friends would have to step in to try and bring him back to his senses.
Naruto would probably be heartbroken. He loves Hinata deeply, so finding out she might have cheated would shatter him.
He could also feel angry. After all, he has fought for his friends and the village. To be betrayed by someone like Sirzechs would make him want to prove his innocence. He might start training even harder to show that he is not the bad guy Sirzechs is making him out to be. And he would likely try to find evidence to clear his name.
Naruto would be extremely hurt. He's a very emotional person who values friendship deeply. He'd probably first try to understand why Yugao did it. He might be in denial at first, thinking it's some kind of misunderstanding.