One possible reason could be a traumatic event. Maybe he witnessed something so horrible that it made him shut himself off from everyone. For example, if he saw his friends in great danger and couldn't save them in time, it might have led to his silence as a form of self - blame.
It could be related to some kind of curse or jutsu gone wrong. There might be a hidden enemy who cast a spell on Naruto that restricts his ability to communicate. This would be a very interesting plot point as it would force Naruto to find a way to break the curse while also dealing with the isolation.
Perhaps Naruto is in a state of deep depression. He has faced so many challenges and losses throughout his life that he has simply given up on talking to others. He may feel that no one truly understands him and that his words would be of no use, so he chooses silence as a form of protection.
Chapter 43 is the strongest chapter-level answer because it starts from The moment He Yun willingly sat next to Jiang Li and even took off his... and follows through on Just as she turned her gaze away, the other party huffed and withdrew her....
Look to Chapter 26 for the clearest answer. It begins with Shen Lan was bent over processing a large stack of press briefs on her..., keeps building through She was nearly forty years old, but because she took good care of herself..., and lands on If you think you can use our family connection to.
Chapter 32 is the strongest chapter-level answer because it starts from You should know, an ID photo is like a mirror for demons. and follows through on With airflow comes water flow, and your fortune will naturally improve."....
A practical answer is Chapter 61, because it turns the idea into a concrete scene. The chapter opens with Hahahaha, oh my god, Jiang Li's mouth is even more venomous., adds pressure through The man's expression darkened for a moment., and ends on A cold shower is pretty normal, right?.
Look to Chapter 22 for the clearest answer. It begins with Hearing this, Su Yinwan looked at Shang Shaojing with a face full of..., keeps building through Shang, but it's not necessary;
Look to Chapter 22 for the clearest answer. It begins with Hearing this, Su Yinwan looked at Shang Shaojing with a face full of..., keeps building through Shang, but it's not necessary;
The best chapter pointer here is Chapter 24, "The Cause of Jiang Shixu's Illness". It opens with Not only that, even the non-mainstream photos she had previously posted on... and closes on Shi Xu rarely feels like going out, so that's nice." Aware that he....
Chapter 26 is the strongest chapter-level answer because it starts from Shen Lan was bent over processing a large stack of press briefs on her... and follows through on If you think you can use our family connection to have me handle this....
A practical answer is Chapter 29, because it turns the idea into a concrete scene. The chapter opens with Big brother, it's me..." The shadow suddenly spoke and it was Jiang..., adds pressure through Learning from experience, Jiang Yan chose to stand next to Lin Manru this..., and ends on Big.
Chapter 35 is the strongest chapter-level answer because it starts from Shining Transformation Trip's filming location was set on the distant... and follows through on Brother is really hardworking, actually arriving at the same time as the....