The Naruto fandom would likely be very divided. Some fans might be intrigued by this unique and unexpected plot twist, seeing it as an interesting exploration of an alternate Naruto universe. However, many fans would probably be quite shocked and even appalled, as it goes against the traditional understanding of the characters and the series.
Kakashi might be initially surprised. But then, he would probably use it as a teaching moment for Naruto. He could say something like 'Naruto, stealing is not the way of a ninja.' And then give him a punishment like extra training.
There are many interesting fanfictions on this topic. Some might explore the relationship between Kakashi's father, Sakumo Hatake, and the events in the Naruto world that we know of. It could delve into his past missions, his influence on Kakashi's upbringing even though he passed away early. Maybe in some fanfictions, he has a connection to some of the main plotlines that Naruto is involved in, like the overarching story of the shinobi world and its conflicts.
Kakashi's reaction would be complex. He is a man who has lost many people in his life. But Naruto was special. He would hold Naruto tightly, his hands trembling slightly. He might try to use some of his own chakra to keep Naruto alive a little longer, but deep down he knows it's futile. His face would show a mixture of pain, regret, and love. He would remember all the times he trained Naruto, all the lessons he taught him, and how Naruto had surpassed all expectations.
Kakashi would likely be very concerned. He would immediately assess Naruto's injuries. If they were serious, he would use his medical skills to start treating him right away. His first reaction would be to make sure Naruto was stable and out of immediate danger.
Kakashi might immediately offer a comforting presence. He could put his hand on Naruto's shoulder and just be there silently, letting Naruto know he's not alone.
Kakashi may also get angry. Angry at the people or things that caused Naruto to get those scars. This anger could fuel his determination to make Naruto stronger, so that he can better defend himself in the future. He might then intensify Naruto's training, all while having a new - found sense of protectiveness towards Naruto.
Well, in Naruto fanfiction where Naruto humiliates Kakashi, it's a bit of a tricky concept. On one hand, fanfiction is a space for creativity and exploring different scenarios. But we have to consider the relationship between the two characters in the original series. Naruto looks up to Kakashi in many ways, so for him to humiliate Kakashi goes against the grain. It might be interesting if it's part of a story about Naruto growing in power and challenging his old mentors in a respectful way, but just blatant humiliation might be seen as disrespectful to the source material.
At first, Kakashi might try to distance himself from Team 7's possessiveness. He values his independence and doesn't want to feel smothered. However, as he realizes that their actions are coming from a place of deep love and loyalty, he starts to accept it more. He may even start to rely on them a little bit, for example, allowing them to help him with his paperwork or other small tasks that he usually does alone. This shows a new level of trust and closeness between them.