Sasuke would probably be more aloof about it. He might see it as another sign of Naruto's uniqueness and be a bit jealous that Naruto always seems to have something new and different about him. However, deep down, he would also be curious and keep an eye on Naruto to see how this new development affects his strength.
Sakura might be initially shocked but then she would be determined to help Naruto find out what's wrong. She could start researching in the hospital's library for any medical or historical records related to such a phenomenon.
Shikamaru would likely find the whole situation tiresome. He might think it's a bother and wonder why Wendy has to have a crush on Naruto. Sasuke would probably be indifferent at first. He has his own goals and isn't really interested in Naruto's love life. However, if Wendy's crush starts to interfere with Naruto's progress in some way, Sasuke might step in and tell her to back off. Naruto's friends like Choji and Kiba would probably tease Naruto about Wendy having a crush on him, which could make Naruto a bit embarrassed.
Sakura might be initially shocked and then start laughing uncontrollably. She would probably tease Naruto about it for a while. Sasuke, on the other hand, would likely just give a slightly raised eyebrow and then act as if it's not a big deal, but deep down he might be a bit amused. Kakashi would probably make a dry joke about it.
Sasuke might be initially suspicious of the tiger. He'd see it as a potential threat or distraction for Naruto. But as he sees how well they work together, he might start to respect the bond.
Sasuke would be extremely suspicious. He has always seen Naruto as his rival and a symbol of the village's hope. If Naruto starts acting like Pein, Sasuke would think it's some kind of trick at first. He might even be ready to fight Naruto to figure out what's really going on.
Kakashi would likely be amused by the whole situation. He might give Naruto some tips on how to blend in better as a girl, using his own knowledge of disguise techniques. Iruka would be more concerned about the reasons behind Naruto dressing as a girl and would make sure Naruto is comfortable with it. He would also be there to support Naruto if any of the other villagers had a negative reaction.
Sakura would be very concerned. She has known Naruto for a long time and has seen his growth. She would probably try to be there for him, using her medical skills to make sure he's physically okay and offering emotional support. For instance, she might sit by his side and talk to him about his feelings, just like she did when they were younger.
Some of the male characters might be a bit flustered around Naruto as a girl. For example, Kiba might act differently, not quite sure how to interact with her in this new form. Hinata, on the other hand, could become even more shy. She already had a crush on Naruto as a boy, and now with Naruto as a girl, her feelings could be even more complex. The Akatsuki members, if they were to encounter Naruto in her new form, might underestimate her at first. But Naruto, with her indomitable spirit, would soon show them that she's still a force to be reckoned with, regardless of gender. And the reactions of the characters would not only be about how they see Naruto, but also how Naruto's new form affects the power dynamics and relationships within the Naruto universe.
The characters close to Rias might be relieved. If they see Naruto as an outsider or a potential threat, his leaving would be a good thing for them. They would probably go back to their normal routines without Naruto's presence causing any disruptions. For example, some of Rias's devil comrades who are more traditional might not like Naruto's different ways and values.
Sakura would be shocked and immediately try to protect the villagers. She might use her medical ninjutsu to heal any injured villagers and then try to subdue Naruto. She would probably be very vocal about how Naruto's actions are wrong and try to bring him back to his senses.
Sasuke might be a bit taken aback at first. He's used to Naruto's normal look, and this change could make Sasuke see Naruto in a new light, perhaps as a more formidable opponent or an even stranger ally. Sakura would probably be shocked too. She might tease Naruto about it at first but then grow to accept it. Kakashi would likely raise an eyebrow and make a comment about how Naruto is always full of surprises with his new look.