Well, his friends might start to feel like he's drifting away. Since he's hiding his strength, he can't fully participate in training or battles as they expect. For example, Sakura might think Naruto is being lazy or not trying hard enough, which could create some tension between them.
Another idea is that Naruto has to hide his strength because he discovers a conspiracy within the village. By feigning weakness, he can gather evidence about those who are plotting against the village without raising suspicion. He might pretend to struggle in normal missions while actually being far more capable.
Maybe they hide their strength in order to protect their relationship. They don't want to draw too much attention to themselves as a couple who are also very powerful. So they act normal in the village, but when they are on secret missions for the Hidden Leaf, they show their real capabilities.
In some fanfictions, Naruto might obtain super strength through special training. For example, he could be pushed to his limits by a new and powerful mentor who has unique training methods. This could involve extreme physical and mental challenges that force his body and chakra to evolve in ways that give him super strength.
One common theme is loneliness. Even though Naruto has friends, the pain of his past, like being an orphan and ostracized as a child, can still make him feel alone at times. Another theme could be self - sacrifice. He might hide his pain because he doesn't want to burden others, especially if he thinks his pain is a small price to pay for the safety or happiness of his friends and the village.
It can create a lot of misunderstandings. Other characters might misinterpret his actions because they don't know his true feelings. For example, if he's hiding his feelings of love for a character, that character might think Naruto is just being friendly and not realize his deeper emotions, which can lead to all sorts of relationship - based plot twists.
The reason why the Crown Prince hid his strength in " Celebrating Years " was to defeat the Second Prince and obtain the throne. On the surface, the Crown Prince was reckless and unwise. The purpose of acting dumb was to numb the other party and make the other party let down his guard. Furthermore, the Crown Prince's position was already very dangerous. He needed to hide his strength in order to survive in the Imperial Palace. Therefore, the Crown Prince hid his strength in order to gain an advantage in the struggle for power.
Prince Qing Yuannian hid his strength in order to defeat the Second Prince and obtain the throne. On the surface, he appeared reckless and unwise. The purpose of acting dumb was to numb the other party and make the other party lower their guard. The Crown Prince's position was already very dangerous. He needed to hide himself in order to survive in the Imperial Palace. In addition, the Crown Prince's hidden strength was also to balance the strength of himself and the Second Prince, as well as to play a more smooth role in the process of fighting for the throne.
In < Celebrating Years >>, the Crown Prince hid some of his strength. Although he looked like a weak prince on the surface, he actually had deep martial arts cultivation and shrewdness. He was good at using the people around him to achieve his goals, and he often planned all kinds of conspiracies behind the scenes. In addition, at the end of the novel, the Crown Prince also displayed his powerful inner energy and combat skills. He displayed an outstanding performance in the duel with Fan Xian.
I recommend the novels "Future Assault of the Whole People" and "Dragon Blood Mercenary" to you. The main character of "Future National Assault" had transmigrated with the National Assault Game System. He possessed a useless person, led a gunner to rise up, and easily played the changed Earth with mercenaries. The main character of "Dragon Blood Mercenary" was a mercenary. His mercenary team had many hidden members who took risks to protect the country and the people. I hope you like this fairy's recommendation. Muah ~😗