Maybe in this fanfiction, Naruto has some sort of curse on his eyes. By hiding them, he is trying to prevent the curse from affecting others or being exploited by his enemies. It could be a dark and dangerous power that he has to keep in check, and hiding his eyes is part of that self - control.
One possible reason could be that his eyes hold a special power that he doesn't want others to discover easily. For example, it might be a new type of Sharingan or a unique ability related to his Uzumaki heritage that he needs to keep secret to protect himself or those around him.
His friends might react with shock and confusion. They might not understand why he has been hiding this from them, and it could cause a rift in their relationships until he explains the reasons behind it. For example, some friends might feel betrayed that he didn't trust them enough to share this secret.
Maybe he wants to surprise his opponents in battles. He could be waiting for the perfect moment to reveal his full power and turn the tables on his enemies.
It could also be part of a strategic move. By hiding his bloodline, he can surprise his opponents in battle. They would underestimate him based on not knowing about his true powers, and then he could turn the tables on them when the time is right. This gives him an edge in combat situations.
He might use some special jutsu or seals. For example, he could use a sealing technique to suppress the signs of his bloodline. This way, others wouldn't be able to detect it through normal means like sensing chakra.
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 a Naruto fanfiction with red eyes, he might gain this trait as a result of a new power-up. For example, he could encounter a powerful sage or a mysterious entity that bestows him with this red - eyed form. His abilities would likely change as well. He could have enhanced perception, like being able to see chakra more clearly or even predict his opponents' moves better. His friends might be initially shocked but would soon accept this new Naruto as he uses his powers for the good of the village.
Naruto's white eyes in Mandarin could be said to be Naruto's white eyes or Tou Mumu Ru's white eyes.
The characters included the male lead, Uchiha Tsuki, the female lead, Yosumei, and the female supporting character, Yakura. Naruto in the Eyes of Samsara Author: I'm a Trash Big Orange Cat. It's a light novel/derivative Doujinshi novel. It has the elements of system flow, relaxation, hot-bloodedness, and leveling. It's finished and can be enjoyed without worry. [User recommendation: In Naruto World.] It was very powerful to have Shura Eyes. It was even more awesome to have the Reincarnation Eye. However, when the guy with the Reincarnation Eye wanted to cheat at the same time… How invincible would that be? This made people sigh. Turtle, hanging on the wall is really awesome! I hope you will like this book.
He might want to protect himself. If others know how smart he is, he could become a target. Enemies might see him as a greater threat and go after him more aggressively.
Maybe he feels betrayed. In the original story, Naruto has faced a lot of discrimination in Konoha when he was young. So in the fanfiction, it could be that some similar or new issues make him decide to hide.