One possible plot could be that they discover their brotherhood through a mysterious force. Maybe Naruto is on a mission and gets transported to the One Piece world. There, he meets Ace and they somehow sense a connection. Then they start to explore their shared past and figure out they are brothers. Along the way, they face challenges together, with Naruto using his ninja techniques and Ace his pirate powers.
Well, the plot could involve Naruto having some of Ace's memories. Maybe he has a strange attraction to the sea like Ace did. He might also have a natural talent for using fire - like techniques in a way that's related to Ace's devil fruit powers in a more Naruto - style way, like creating fire - based jutsus.
Well, the plot might start with Naruto being confused about his new identity as Hashirama's brother. He could struggle with how this changes his self - perception and his relationship with his friends. Hashirama, on the other hand, could be overjoyed to have his long - lost brother back. They might work together to improve the village, using Hashirama's wisdom and Naruto's modern - day knowledge. But there could also be opposition from some in the village who fear the power that Naruto and Hashirama together possess. This could lead to internal conflicts and battles as Naruto and Hashirama strive to prove that their intentions are good for the village.
The plot could involve them discovering their brotherhood. Maybe they start off in different worlds and then some magical or mysterious event brings them together. They then realize they are brothers and start to explore their combined powers to fight against a common enemy.
Well, one possible plot could be that since Naruto is Minato's brother, he is not ostracized by the village. Instead, he is seen as a potential heir to Minato's legacy. This would change his entire character arc. He might not have the same drive to prove himself, but rather focus on living up to Minato's name. There could also be a plot where they face a common enemy together, and Naruto's bond with Minato helps him unlock new powers or techniques. Another aspect could be the exploration of their family secrets and how it impacts the whole Hidden Leaf Village.
One possible plot could be that Naruto somehow gets transported to the DC universe where the Ace Justice League exists. He could initially be seen as a threat due to his strange powers. But as they get to know him, they realize his good intentions. Naruto could teach the League some of his ninja techniques, like how to use chakra to enhance their physical abilities. And in return, the League could introduce Naruto to advanced technology and different ways of justice in their world.
Well, in the original Naruto and One Piece universes, Naruto has no relation to Ace. However, in fanfiction, anything can be possible. Writers can create an alternate universe where Naruto is Ace's brother through creative plot devices. They might come up with some sort of cross - dimensional or magical connection that binds them as brothers.
The plot could involve Naruto finding himself in a situation where he has to interact with Rias's brother. The brother, being too involved in his own world of power and politics, simply brushes Naruto off as unimportant. Naruto then decides to prove himself not through grand displays of power, but through his kind heart. He helps those in Rias's group who are being overlooked or underestimated, just like he was in his own village. This catches the attention of Rias's brother who starts to see the value in Naruto he had previously neglected.
Perhaps Hagoromo's brother was wrongly accused of something in the past and sealed away. Naruto discovers his existence and frees him. In return, the brother tells Naruto the true history of the ninja world, including secrets about the origin of chakra that no one else knows. This knowledge helps Naruto to bring about a new era of peace and understanding among all the ninja clans.
The plot could revolve around his early life. Maybe he was always in Madara's shadow, and the fanfiction could explore how he tried to find his own identity. He could start training secretly to develop unique skills that set him apart from Madara.
The plot could start with Naruto growing up in the Uchiha clan as Sasuke's little brother. He might face discrimination due to being the Jinchuriki, but Sasuke would be protective. They could train together, with Sasuke teaching Naruto some of the Uchiha techniques. Later, when the clan is massacred, Sasuke might be even more determined to get revenge, and Naruto would be by his side, trying to stop him from going down a dark path.