It could be the very people who banished Naruto in the first place. They might fear his new - found power and try to stop him from returning to the village or from getting revenge. They would likely use underhanded tactics to try and take him down.
Maybe Naruto gets banished and ends up in a place full of ancient and powerful artifacts. He discovers how to use these artifacts to enhance his own abilities. He also forms alliances with some outcasts in this new place who share their combat skills with him. As a result, he becomes powerful not just in terms of his ninjutsu but also in terms of strategy and teamwork.
Well, one plot twist could be that Naruto discovers a hidden ancient power during his banishment. Maybe he finds a long - forgotten jutsu in a desolate place. Another could be that he forms unexpected alliances with former enemies who now see his banishment as unjust. For example, some of the minor villain clans might join him, seeing a chance to overthrow the existing power structure in the shinobi world.
Naruto's character could develop a more jaded side. After being banished, he might start to question the values he once held dear. However, his underlying kindness still remains. He becomes more cautious and calculating with his new power, not wanting to be used again.
Maybe a group of outcasts similar to Naruto. They could form a team with Naruto and they all have their own unique abilities. For instance, one might be able to control the elements in a very different way than the normal shinobi in Konoha. They work together to survive in the banished land.
One interesting plot could be Naruto going on a journey to find a way to clear his name. He might meet new allies who believe in his innocence and together they face various challenges.
One possible reason could be political intrigue. Maybe some powerful figures in the Hidden Leaf village see Naruto as a threat to their power. Since he is a Jinchuriki and has growing influence among the younger generation. They might engineer his banishment to get him out of the way.
At first, Naruto is likely to be confused and hurt. He has always considered the Leaf village his home and the villagers his family, so being banished would be a huge shock. He might feel betrayed.
Hinata could also be a common character. She may try to help Naruto secretly, or be heartbroken by his banishment and strive to change the village's decision. Another character could be Kakashi. He might be one of the few who believe in Naruto's innocence and try to find a way to bring him back to the village.
He could marry Hinata. Even though he's banished, Hinata might follow him because of her deep love for him. Their relationship could develop further outside the village, and they could get married and start a family.