Maybe Kakashi. He's been Naruto's teacher and mentor. He has the skills and the loyalty to Naruto. He could use his Lightning Blade technique to quickly reach Naruto during the fall and carry him to safety.
He could get seriously injured. The Hokage monument is very tall, and the fall would be a long one. Naruto might break his bones or worse.
Sakura would be extremely distraught. She has always cared deeply for Naruto, and seeing him in such a dangerous situation would make her rush to his aid immediately. She might use her medical ninjutsu to heal him if he's injured. Kakashi, on the other hand, would be shocked but also proud that Naruto has the courage to face his inner demons in such a drastic way. He would try to understand Naruto's motives and help him get back on track.
One possible plot could be that Naruto is facing extreme self - doubt. Maybe he feels he has failed the village in some way, like not being able to prevent a major disaster. So, in a moment of despair, he jumps off Hokage Mountain. But then, his friends sense something is wrong and come to his rescue just in time. They then have heart - to - heart talks with him and help him regain his confidence.
The village's morale could take a huge hit. Naruto is a symbol of hope and strength. If he jumps off the monument, it would make the villagers question their own safety and the stability of the village. Politically, it could cause unrest as the village leaders would have to deal with the aftermath and try to keep the situation under control.
In some fanfiction scenarios, Naruto might jump off the Hokage monument to follow someone or something. For example, if there is a mysterious figure or a spiritual entity that he believes he needs to follow, and the only way seems to be by jumping. It could also be a symbolic act of breaking free from the expectations that come with being associated with the Hokage monument.
On the positive side, it could boost his reputation among some of the younger ninja. They might see him as a fearless and rebellious figure. However, it could also create a divide in the village. Some would admire his boldness while others would condemn his actions as reckless and irresponsible.
Shikamaru is another possibility. He is known for his strategic mind. As Hokage, he could use his intelligence to make wise decisions for the village. He may not have the brute strength of Naruto or Sasuke, but his ability to plan and analyze situations would be invaluable in leading Konoha.
Perhaps a perk is the ability to shape the future of the ninja world. As Hokage, one can inspire the younger generation of ninjas. They can create new ninja academies or training programs. They also have the power to pardon or punish ninjas according to their deeds, which helps in maintaining law and order in the village.
Sasuke could also be a possibility for the 6th Hokage in the fanfic. He has grown stronger over the years and his unique perspective on the ninja world could bring new ideas to the leadership of the Hidden Leaf. He might start off as a controversial choice but prove himself through his actions in protecting the village and making tough decisions.
Perhaps Naruto jumps off the Hokage heads as part of a training exercise in the fanfiction. He might be testing his new skills, like a new form of chakra control or a new jutsu that allows him to land safely. It could also be a bet with his friends, like Sasuke or Sakura, to prove his courage and abilities.