The Naruto community's reaction could be mixed. Some might create amazing fan art based on this pairing in the fanfiction, fueling more interest. Others might start debates on forums about whether it's a good or bad idea. Overall, it would create a lot of buzz and discussion within the community.
Some in the Naruto community might be really excited about it. They like to see new and different pairings. It gives a fresh take on the Naruto universe. Fans who enjoy exploring different character relationships would be all for it.
Naruto's reaction could be complex. On one hand, he would be happy to find someone else from his clan. He has always been proud of his Uzumaki heritage despite not knowing much about it at first. But on the other hand, he might be a bit cautious. Karin has been associated with some not - so - good groups in the past. However, overall, his positive nature would probably lead him to approach Karin with an open mind and try to build a connection with her based on their shared Uzumaki roots.
One possible plot could be that Naruto, in this fanfiction, realizes Karin's strength and her unique personality. He starts to date her to understand her better. They might go on missions together and during those, their relationship deepens. For example, they could be on a mission to rescue a kidnapped shinobi. Karin uses her sensing abilities to track the enemy, and Naruto is impressed by her skills. This leads to more romantic moments between them.
Sakura might be a bit surprised at first, but she would probably come around and be happy for Naruto. Sasuke would likely be indifferent on the surface but secretly hope that Naruto is making the right choice. Hinata might be a bit sad that Naruto didn't choose her, but she would be polite and congratulate them.
In the Naruto saves Karin fanfic, the act of saving Karin by Naruto can have a profound impact on their relationship. Karin has always been on the periphery of Naruto's world, but this event would bring her closer. She may start to believe in Naruto's ideology more strongly. Naruto would also develop a more protective stance towards Karin. This new dynamic could lead to more interactions between them in the future, both in battle and in more personal, emotional situations.
Karin could be heartbroken. She might initially be angry and feel betrayed, lashing out at Sasuke for choosing Sakura over her.
Eventually, Naruto could grow resentful. If the ignoring persists for a long time, he might start to think that Kakashi doesn't care about him at all. This could change Naruto's attitude towards Kakashi and might even make him more rebellious in his training or actions. However, deep down, he still probably hopes for Kakashi's recognition and approval.
He would probably be very angry. Naruto has always been a free - spirited person, and being experimented on against his will would be a huge violation of his rights. He might initially try to resist physically, but as the situation gets more complex, he could start to plot his escape and revenge.
Naruto might initially be shocked and angry. He has a strong sense of justice and being kidnapped goes against everything he stands for. He would likely try to fight back immediately, using his basic ninja skills and his determination. For example, he could try to use his Shadow Clone Jutsu to create distractions and escape.
Naruto might initially be very confused and hurt. He loves his father and the village, so being banished would be a huge shock to him.
Naruto might be very forgiving right away. He has always had a big heart and cared deeply for Sakura, so he could just accept the apology with a big grin and say it's all in the past.