One possible reason could be jealousy. Maybe Naruto has been getting more attention from the village elders or teachers because of his potential. His friends, feeling left out or overshadowed, might start to ignore him out of envy.
There could also be friends who are so loyal to Naruto that they would consider following his request if they truly believe it's for the greater good. However, they would be deeply pained by it. Kakashi, for instance, might understand Naruto's selfless nature but would also struggle with the moral and emotional implications of taking his life.
One possible reason could be jealousy. Maybe Naruto has achieved something great and his friends are envious. Another reason might be a misunderstanding. There could have been some false rumors or misinterpretations of Naruto's actions that led his friends to believe he wasn't trustworthy or a good friend.
He might overcome the betrayal by focusing on his own growth. By becoming stronger both physically and mentally, he could rise above the pain of betrayal. He could also look back on the good times with his former friends and use that as a motivation to move forward and prove himself.
In such a fanfic, Naruto would likely be deeply hurt. His trust in his friends being shattered could lead to him becoming more isolated. He might start to question his own worth and his ninja way. Maybe he would turn away from Konoha for a while to figure things out on his own.
He might be shocked. In the fanfic, if he sees things like his friends' future achievements or the new threats that emerge, it would surely startle him. For example, if he discovers that one of his friends has a family of their own and has become a great leader in the village, he would be proud but also a bit surprised at how much has changed.
His friends would likely be shocked. Shikamaru, for example, would probably be disappointed in Sakura. He might try to comfort Naruto and tell him to think rationally. Choji might be angry on Naruto's behalf and want to confront Sakura. And Sasuke, if he's around, might have a complex reaction. He might feel a strange sense of satisfaction that Naruto is finally seeing Sakura's 'true' side, but also a bit of pity for Naruto.
With his usual determination. Naruto has always been one to face difficulties head - on. So, even if he's shocked by what he sees in the fanfic's future, he'll likely try to find solutions immediately.
Some of Naruto's friends could be really enthusiastic about his new friendship with Tora. Choji might offer Tora some of his favorite snacks. Ino could try to dress Tora up in cute little outfits. However, Neji might be a bit skeptical at first, thinking that Tora could be a distraction for Naruto. But as he sees the positive impact on Naruto, he would come around.