One possible plot could be that the Juubi from Naruto somehow breaks through dimensions and ends up in the Bleach universe. This could cause chaos as the spiritual energy in the Bleach world reacts to the Juubi's massive chakra. Ichigo and Naruto might team up to stop the Juubi. Naruto could use his sage mode and Rasengan techniques, while Ichigo uses his Bankai. They would have to learn to combine their powers and fighting styles to defeat the Juubi and send it back to its own universe.
Well, it could be about Naruto having to face a new and more powerful form of the Juubi. Maybe the Juubi has some new abilities or is being controlled by a new villain. Naruto would then have to gather his friends and allies, train harder, and discover new powers within himself to defeat this new threat.
Well, one possibility could be that Naruto, with the power of the Juubi, enters the DxD world. He might use his ninja skills and the Juubi's immense power to face off against the devils and other supernatural beings in the DxD universe. Maybe he forms alliances with some of the characters there, like Issei and his friends, and together they fight a common enemy that threatens both the ninja world and the DxD world.
The plot could involve the Juubi's chakra influencing some of the demons in the Inuyasha world. Naruto arrives and has to figure out how to stop this chaos. He might teach Inuyasha some of his ninja skills, and Inuyasha in turn could show Naruto how to deal with the demons. They could also find that the Juubi has some ancient connection to a powerful artifact in the Inuyasha world, and they have to stop an evil force from using this connection for their own gain.
One possible interesting plot could be a crossover where a character from another universe gains the Juubi eye in the Naruto world. This new power could disrupt the balance of power, leading to alliances and rivalries being formed in new and unexpected ways.
In this 'naruto the juubi crossover mass harem fanfiction', the plot might revolve around Naruto being thrust into a situation where the Juubi's energy somehow creates a harem around him. It could start with Naruto's battle against the Juubi. After some kind of encounter with the Juubi's power, female characters from various places start to flock to him. They could be attracted by his new - found power related to the Juubi or some other mysterious connection. Naruto would then be in a position where he has to balance his ninja duties, understanding the Juubi, and dealing with his new - found relationships.
One possible plot could be that the Juubi somehow gets transported to the Naruto world during a strange rift in space - time. Naruto and his friends have to figure out how to deal with this powerful and chaotic entity. They might initially try to fight it, but then realize they need to find a way to seal it again, like they did with the other tailed beasts. This could lead to new alliances and power - ups for the characters as they struggle to protect their world.
One possible plot could be that Ichigo and Naruto meet in a dimension that's in between their two worlds. They initially mistake each other for enemies but then realize they both have a common goal of protecting their respective universes from a new, powerful threat that somehow has the ability to cross between the Naruto and Bleach worlds. They team up, with Ichigo's sword skills and Naruto's ninjutsu creating some really cool battle scenes.
One possible plot could be that Naruto, with his powerful ninja skills, gets transported to the Bleach universe. He teams up with Ichigo. Naruto's ability to create multiple clones could be used in unique ways in battles against Hollows. For example, he could send clones to distract the Hollows while Ichigo goes in for the final strike.
Definitely Naruto and Ichigo. They are both strong - willed protagonists. Naruto's positive and determined attitude could clash and then blend with Ichigo's more brooding and intense personality. It would be interesting to see how they communicate their different fighting styles and powers to each other.
The plot of such a fanfic might involve a villain who has the powers of both the Akatsuki (from Naruto) and the Arrancar (from Bleach) and is causing chaos in both worlds. Naruto, with his Rinnegan, and Ichigo are the only ones who can stop this villain. Naruto could use his Rinnegan - related abilities like the Six Paths powers to combat the villain's dark techniques. Meanwhile, Ichigo uses his Bankai and Hollow powers. The two of them would have to learn to work together, overcoming the differences in their powers and fighting styles.