A new, unknown villain could be the cause. This villain might have a special power related to mind control or mental manipulation. They target Naruto because of his status as a hero in the ninja world. By making Naruto lose his mind, they could throw the entire ninja world into chaos.
He could start with simple objects. Maybe he'd practice moving small pebbles around, focusing on controlling their speed and direction. Meditating could also be a part of his training, to clear his mind and enhance his concentration for better control over the mind - moving ability.
Well, his friends might be in awe of him at first. Some, like Sakura, could be a bit jealous of this new power he has. But Naruto, being Naruto, would probably use it to protect his friends more effectively, which could strengthen his bonds with them in the long run. His enemies, on the other hand, would be more cautious around him, seeing him as an even greater threat.
In a fanfiction scenario, Naruto might be in a calm and quiet forest glade. He is there to meditate and also practice his slashing attacks. As he focuses in the quietness, he realizes that his slashing moves can be combined with his natural energy absorption. So he starts to develop a new type of slashing move that is powered by both his chakra and the natural energy around him. This makes his slashes more powerful and also gives them a unique greenish glow. His friends are amazed when he shows them his new technique later.
In this fanfiction, there could be a villain who has the ability to manipulate Naruto's mind. The villain might use this power to make Naruto turn against the Hidden Leaf Village. Naruto, without control of his own mind, could start causing chaos within the village, like attacking important buildings or trying to steal important ninja secrets.
Well, he could start making really rash decisions. Maybe he'd attack his friends by mistake, thinking they were enemies. Since he's lost his mind, his usual judgment would be out the window.
One way for Hinata to move on could be through self - discovery. In fanfiction, she might focus on her own personal growth outside of her feelings for Naruto. She could explore new hobbies or develop her skills. For example, she could train more intensively in her ninja abilities, which would not only make her stronger but also give her a new sense of purpose. Another aspect could be making new friends. Instead of always being centered around Naruto and his circle, she could interact with other characters in the Naruto universe who she hasn't had much to do with before. This would expand her social circle and give her different perspectives on life.
His departure would definitely put a strain on his relationships. His close friends like Sasuke, if he is back in Konoha at that time, would have mixed feelings. They might worry about Naruto but also be a bit angry that he left without consulting them. Naruto's younger friends like Boruto would be confused and miss him a great deal, and this could lead to some distance in their relationships.
In 'naruto moves on fanfiction', Naruto is the main character for sure. But other important characters could include his new friends or mentors that are created specifically for this fanfiction. For instance, there could be a wise old ninja from a far - off land who becomes Naruto's guide in his new adventures. Also, characters from the original series like Kakashi could still play significant roles.
There could be new characters created specifically for this fanfiction. Maybe a young Suna shinobi who becomes Naruto's guide in Suna, showing him around the village and introducing him to the local way of life.