Maybe the Kyuubi inside Naruto is somehow related to the powerful yokai in Inuyasha's world. Inuyasha and Naruto initially clash due to their different personalities. Naruto is all about friendship and protecting the village, while Inuyasha is more focused on his personal revenge. But as they get to know each other, they learn from each other's strengths. For example, Naruto could teach Inuyasha about the power of teamwork, and Inuyasha could show Naruto some unique combat techniques against spiritual enemies.
A possible plot is that Kagome's arrow, which has spiritual power, is misfired and creates a rift in time - space that sucks Naruto and his team into Inuyasha's world. The shinobi then have to adapt to the new environment. Sasuke might be intrigued by the power of the Tessaiga, and try to learn how to use similar spiritual weapons. Meanwhile, Naruto uses his Rasengan against the demons, and they all start to figure out a way to get back to their own world while also dealing with the local threats.
One interesting plot could be that Naruto and his friends are on a mission and accidentally end up in Inuyasha's feudal Japan through some sort of magic portal. There, they meet Inuyasha and his group. Naruto's ninja skills could be put to the test against the demons Inuyasha usually battles. And perhaps they team up to defeat a powerful common enemy, like a super - strong demon that neither group could handle alone.
One possible plot could be that a character from Naruto with the Rinnegan somehow gets transported to the Inuyasha universe. Maybe they team up with Inuyasha and his friends to fight a common enemy. For example, the power of the Rinnegan could be used to counter some of the powerful demons in the Inuyasha world. The character might also introduce new jutsu or abilities to the Inuyasha gang, which could change the way they fight battles.
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 plot could be that Thor somehow gets transported to the Inuyasha universe. Thor's powerful hammer and lightning powers would be a huge asset or a source of conflict. Maybe the demons in the Inuyasha world see Thor as a threat or a powerful ally to be manipulated. Inuyasha and his group might initially be wary of Thor but then realize they can work together to defeat a common enemy, like a powerful demon that is causing chaos across the land.
A plot could involve a spell gone wrong in the Inuyasha world that opens a portal to the Disney realm. Kagome, being from a more modern world, recognizes some of the Disney elements. Mickey Mouse could be the first Disney character they meet. He helps them navigate this new world while Inuyasha is trying to find a way back home. Meanwhile, Disney villains might see Inuyasha as a threat and try to get rid of him. But Inuyasha, with his combat skills, manages to fend them off. In the end, they find a way to close the portal and return home, but not before creating some new friendships and memories.
A cool plot could be that there's a tournament across different anime worlds, and Inuyasha and Naruto are chosen to represent their respective worlds. Along the way, they discover similarities in their pasts, like both having some form of demon - related heritage (Naruto with the Nine - Tails and Inuyasha being a half - demon). They also exchange combat techniques. Naruto teaches Inuyasha how to better use chakra control in his attacks, and Inuyasha shows Naruto some unique sword - fighting skills.
A really unique plot could be a situation where the tailed beasts in Naruto are related to the powerful demons in Inuyasha. For instance, the Nine - Tailed Fox could have a connection to a major demon in Inuyasha's world. This discovery could lead to a journey where Naruto has to travel through the Inuyasha world with Inuyasha and Kagome to find out the truth about this connection and how it can help or harm their respective worlds.
A cool plot might be that a dark wizard from Fairy Tail discovers a spell that can open portals to other dimensions and accidentally pulls Inuyasha, Kagome, Shippo, etc. into their world. The Fairy Tail guild decides to help them get back home. But during this time, they realize that there are some similarities between the demons in Inuyasha's world and the dark creatures they fight in their own world. So, they team up. Inuyasha and Natsu could have a friendly rivalry over who is stronger and in the end, they combine their powers to defeat an ancient evil that was awakened by the portal - opening spell.
One possible plot could be that Light Yagami discovers the existence of demons from the Inuyasha world. He might see them as a new type of 'evil' to be eradicated. He could start using the Death Note on demons, which would draw the attention of Inuyasha and his group. Inuyasha would initially be confused about these strange deaths and then realize that a human is causing them. This would lead to a conflict as Inuyasha believes in slaying demons in a more 'honorable' way and not through this strange notebook's power.
One possible plot could be that Inuyasha and his friends are somehow transported to the world of The Walking Dead. Inuyasha's sword, Tessaiga, could be effective against the zombies as it can cut through almost anything. They could team up with the survivors in the Walking Dead world. Kagome's spiritual powers might also be useful in detecting the zombies from a distance or even purifying them in some way.
One possible plot could be that Naruto and his team are on a mission in a strange new land and accidentally cross paths with Inuyasha and his group. They initially mistake each other for enemies but then realize they are both fighting against various forms of evil. They could then team up to defeat a powerful demon that neither group could handle alone.