One possible significance could be a sign of his growth and the battles he has endured. His scars are like a visual record of his journey, showing how he has overcome difficulties. They might also be a way to connect with other characters on a deeper level, as they can see the physical toll his life has taken.
Some characters might be shocked and saddened. They may have known Naruto as a strong and energetic person, and seeing his scars would make them realize the hardships he has faced.
He might show his scars to Sasuke. Given their complex relationship, it could be a powerful moment between them, a way to show Sasuke that Naruto has also faced great pain in their separation and the events that followed.
One possible reason could be that he doesn't want others to pity him. Naruto has always been a proud and strong - willed character. His scars might be a reminder of painful past experiences, and he prefers to deal with them privately rather than showing vulnerability to others.
In the context of fanfiction, it might also be a plot device to explore Naruto's vulnerability. It could lead to new character developments, such as others seeing him in a new light. Maybe it causes some characters to re - evaluate their relationship with him, while for others it could be a source of inspiration, seeing that even someone as strong as Naruto has his own set of hardships.
Kakashi could be involved too. Given that Kakashi has trained Naruto and seen his growth, Naruto might trust him with his secrets. He could reveal his thoughts on how he wants to change the ninja world for the better and the steps he is planning to take in the future.
In the fanfiction, Naruto might use his chakra control skills to create a genjutsu that alters the perception of those who see him. He could project an image of his unscarred self over his actual body. For example, he focuses his chakra on the area around his scars and manipulates the light and the way it reflects off his skin in the eyes of others, making the scars seem to disappear.
Another possibility is that he reveals secrets about his parents. He could talk about things his father, Minato, told him in a dream or some information he discovered about his mother, Kushina, that no one else knows. For example, a secret mission they were involved in or a special bond they had with certain characters in the Hidden Leaf Village.
Another possibility is that it could be a part of a self - discovery arc in the fanfiction. Maybe Naruto starts to question his own identity and through various interactions and experiences, he decides to reveal his true gender as a way to be more true to himself.
They would probably be shocked. Since Naruto is such an important figure to them, any big secret would likely cause a stir. For example, if it's about his Nine - Tails secret, they might be initially stunned as they realize how much he has been carrying alone.