He could leave Konoha in search of answers about his parents. Along the way, he meets a mysterious old man who has some knowledge about his family. The old man performs a ritual on Naruto, which unlocks his bloodline. This newly unlocked bloodline might give Naruto the ability to teleport short distances, a power that was once common in his family but had been lost over time.
One idea could be that as Naruto leaves Konoha, he encounters a powerful and ancient creature in the wild. In a battle with it, the extreme stress and need to survive unlocks his hidden bloodline. This new power could be related to some kind of elemental control that is unique to his clan, like a special form of wind manipulation that is far more powerful than what he had before.
In such a fanfic, Naruto might find that his bloodline unlocks a new form of chakra. For example, his normal blue chakra could transform into a more powerful and unique - colored chakra, like purple. This new chakra could have different properties, such as being able to break through any jutsu defenses more easily. As he leaves Konoha, he has to quickly learn to control this new power on his own, without the guidance of his former teachers.
In a fanfic, Naruto's bloodline could be connected to an ancient prophecy that Konoha tried to prevent from coming true. They feared Naruto's potential power from the bloodline. So they isolated him and treated him badly. As he grows up and learns about this prophecy and Konoha's actions to stop it, he starts to hate the village. His bloodline could give him unique abilities like the ability to control a powerful and ancient energy source that Konoha was afraid would disrupt their power structure.
His relationships with his friends like Sasuke and Kakashi would also be affected. Sasuke might understand Naruto's decision on some level, having also left the village before. Kakashi, on the other hand, would be worried about Naruto. He might try to find him and bring him back. This could create some tension between Naruto and Kakashi as Naruto tries to assert his independence.
It could lead to political unrest in Konoha. There might be those who blame the village leadership for Naruto's departure. This could lead to power struggles as different factions try to take control and change the way the village is run. Some might demand more transparency and better treatment of their shinobi to prevent such a thing from happening again.
Konoha's power structure could be affected. Naruto is one of the strongest shinobi in the village. Without him, the village might be more vulnerable to attacks from other villages or threats. They would need to quickly find ways to fill the gap in their defenses.
It could create a sense of unease and fear. Naruto is a very powerful ninja, and if he turns dark and leaves, the villagers would be worried about him coming back as an enemy. It might also lead to a decrease in morale among the ninjas who once considered Naruto a friend or ally.
Maybe there are some dark secrets within Konoha that he discovers in the fanfic. These secrets could be related to the treatment of certain individuals or something more sinister about the village's leadership. Discovering such things could make Naruto decide to leave in order to distance himself from the corruption or unfairness.
His decision could make him more self - reliant. Away from Konoha, Naruto has to depend solely on himself. He'll likely face new challenges that force him to dig deeper into his own abilities and beliefs. This could lead to a more mature and nuanced understanding of his own strength.
Sakura would probably be very worried. She has always cared about Naruto deep down, so she might be constantly trying to find a way to bring him back. Kakashi, on the other hand, would likely understand Naruto's reasons to some extent. He might be sad but also respect Naruto's decision. As for Sasuke, if he is in the village at the time, he could be conflicted. He and Naruto have a complex relationship, and Naruto's leaving might make him realize how much Naruto actually means to him.
In a 'naruto and kushina leaves konoha fanfic', perhaps they leave due to a threat to Naruto's safety that the village can't fully protect against. Maybe some secret organization is after him and they feel they have no choice but to go into hiding outside Konoha.