Sakura would probably be initially very angry. She has strong feelings for Sasuke, but kidnapping is a very extreme act. So she would likely fight back, using her medical ninjutsu skills and combat abilities to try and escape.
Sakura might be completely shocked at first. She might freeze for a moment, not believing what's happening. Then she could start crying tears of joy and say yes immediately.
Sakura might initially be confused. She would probably wonder why Naruto is acting this way all of a sudden. For example, she might try to get his attention by calling his name a few times, but when he doesn't respond, she could be left feeling a bit bewildered.
Sakura might be heartbroken. She's been in love with Sasuke for so long. She could initially go into denial, thinking it's just a temporary thing. Then she might get angry and vow to prove herself to Sasuke, perhaps by becoming an even stronger ninja.
She could be heartbroken. Sakura has always loved Sasuke deeply, so his leaving for Naruto would be a huge blow to her. She might initially be in denial, not believing that Sasuke would choose Naruto over her.
Kim would initially be in shock but quickly shift to her problem - solving mode. She would assess the situation and start formulating a plan. Ron would be freaking out a bit, but he would also try to make light of the situation with his humor. Rufus would be exploring and might accidentally stumble upon some key information about the Chaos Gods. Meanwhile, Bonnie would probably be more concerned about how this chaos would affect her social status, but she might also end up helping Kim in an unexpected way.
Well, Serena would probably be over the moon. She's always been close to both Dan and Blair and would see this as a wonderful union. She'd be there for Blair during the pregnancy, helping her with shopping for baby clothes and giving her advice. Nate, on the other hand, would be more practical. He'd offer to help Dan with any financial or housing arrangements they need to make for the baby. And then there are the more catty friends, like Penelope and Hazel, who might be jealous and make snide remarks about how Dan and Blair got pregnant so quickly, but deep down they're just envious of their relationship.
Sakura might initially be shocked and resistant. She is a strong - willed character, so she could try to fight back or find a way to escape this forced situation. Maybe she would first confront Sasuke about his unacceptable behavior.
She could be confused at first. She might not understand why Naruto is suddenly ignoring her, since they were friends before. So she might try to approach him to ask what's wrong.
He probably gets really protective. Jack might immediately rush to her side and check on her injuries. He'd be worried sick and would want to make sure she gets proper medical attention right away.