She might be disgusted. Smoking isn't a common or acceptable behavior in the ninja world. So Kurenai could immediately tell Naruto to stop and throw away the cigarette.
He might be shocked at first. Naruto is used to seeing Kurenai as an ally, so being hurt by her would be unexpected. He could immediately ask her why she did it. If it was a serious injury, he might struggle to stay conscious while trying to understand the situation.
Hinata might also be determined to prove her innocence or change Naruto's mind. She could start on a journey to find out the real reason behind her banishment and clear her name. She may gather allies and evidence to show Naruto that he has been misled.
She would be heartbroken. Sakura has known Naruto for a long time, and his death would shatter her world. She may become more withdrawn and serious. In the long run, she could use her pain as motivation to become stronger. Maybe she would train harder than ever before to make sure that no one else has to suffer the way Naruto did. She might also start to see Naruto in a different light, realizing all the things she took for granted when he was alive.
Naruto would probably be really confused at first. He respects Kurenai, so he'd be hesitant to fight back right away. He might try to talk to her and ask what's wrong.
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.
Naruto might be initially shocked and heartbroken. He is someone who values loyalty and friendship deeply, so being cheated on would be a huge blow to him.
Naruto would probably be initially cautious but also curious. He has a knack for seeing the good in people, so he might try to befriend the Akatsuki sister. Kurenai, on the other hand, would be more guarded. She is a more experienced ninja and would be wary of any Akatsuki member. But she also might see an opportunity to gain intel from the sister.
He could be in shock at first. Standing there for a moment, not believing what he's seeing. Then, his vampire instincts would kick in and he'd start looking for any signs of what caused her to collapse, whether it's an external force or something internal like an illness.
She might be heartbroken. Hinata, being a shy and sensitive person, would likely retreat further into herself. She may feel that all her efforts to be brave and show her feelings to Naruto have been in vain.