In some fanfiction scenarios, Kurama might abandon Naruto if he believes that Naruto is becoming too corrupted by power. Kurama has a sense of honor in a way, and if Naruto starts to use his power in a way that Kurama doesn't approve of, like becoming overly aggressive or cruel, Kurama could decide to leave. For example, if Naruto starts to use the Nine - Tails' power to dominate others rather than protect them.
Naruto would likely become more determined. He has always been a fighter, and without Kurama, he would have to rely solely on his own skills and training. He might become more stealthy and strategic, since he wouldn't have the brute power of Kurama to fall back on.
The Kurama Brothers could be entities that have a similar origin to Kurama. They might have been part of the same chakra - based creation in the Naruto universe. They could possess some of Kurama's traits like great power and a connection to the natural energy in the world. They are often depicted as having their own personalities, with one being more hot - headed and the other more calm and calculating. Their relationship with Naruto usually involves them using their powers and knowledge to help Naruto grow as a ninja and a person. They might also have their own goals and motives that are intertwined with Naruto's journey.
Well, Kurama might train Naruto by teaching him how to better control and access chakra. Since Kurama has a vast amount of chakra, it could show Naruto unique ways to harness and use it. For example, it could guide Naruto in creating more powerful and complex jutsu by using their combined chakra in a more efficient way.
Well, it could go in many directions. For example, his family might start to search for him, which could lead to a series of adventures where they encounter new characters and face various challenges. His wife, if he has one in the story, might become stronger and more independent in his absence, vowing to bring him back.
Naruto would be devastated. He sees Kakashi as a mentor and father figure. He might initially go into denial, not believing that Kakashi would actually abandon him.
At first, Naruto is likely to be heartbroken. Konoha has been his home, and he has always longed for acceptance from the villagers. So being abandoned would be a huge blow to him.
Kurama might become angry at first. He's a powerful being and being neglected would likely wound his pride. He could start causing some minor disruptions inside Naruto, like making it harder for Naruto to access his chakra.
He could become very determined to find out why Sakura left and try to win her back. Naruto is known for his perseverance, and he wouldn't give up easily on his family. He might also start to question his own actions and wonder if he could have done something differently to prevent this.
It might be portrayed as a very strong and almost spiritual connection. They could be shown as two halves of a whole, with Naruto relying on Kurama not just for power but also for emotional support and vice versa.