Perhaps Naruto's dragon - summoning is linked to an ancient prophecy. In the story, as he starts to summon dragons, it sets off a chain of events where different ninja clans either try to help him or stop him, depending on how they interpret the prophecy. The dragons could also be guardians of some long - lost ninja secrets.
One idea could be a pony being summoned in the Naruto world and having to adapt to the ninja way. For example, it might use its unique pony abilities like magic or flight in combat, which would surprise the Naruto characters.
One idea could be exploring the relationship between Naruto and the slug he summons in more depth. Maybe the slug has a special power that only Naruto can unlock, and they have to go on a journey to discover it.
In a fanfiction, Naruto could change his gender due to a curse placed on him. As a female, he discovers that he has different natural abilities or affinities. For example, he might find that his new form is more attuned to water - based jutsu. He also has to deal with the reactions of his friends like Sasuke, who is initially confused but then accepts Naruto in this new form. Naruto then uses his new identity to bring about a new era of understanding between male and female ninjas in the Hidden Leaf Village.
One idea could be that Naruto is resurrected in a world where all his friends have forgotten him. He has to re - establish his relationships while also dealing with a new threat that emerged in his absence.
Maybe Naruto is adopted by a family outside of the Hidden Leaf village. This would force him to adapt to a new culture and way of life. He could learn different chakra - control techniques or even new forms of ninjutsu that are specific to that village. It could also create a conflict when the Hidden Leaf needs his help but he has loyalty to his new home as well.
One idea could be that Naruto has to find new ways to communicate his strong will and determination without speaking. Maybe he uses sign language that he invents himself, and his friends gradually learn to understand him. This could lead to some really heartwarming moments of connection.
One interesting plot idea could be that Sans uses his mind - reading ability to prevent a major disaster in the Underground. He senses the intentions of a powerful and malevolent force before it can act and is able to rally the other characters to stop it. Another idea is that he reads the mind of a character who is secretly an ally but has been acting strange, and through this he discovers a hidden plan to save the Underground that the character was too afraid to share. Or perhaps he reads the mind of a human who has entered the Underground and discovers their true motives, which are not as bad as everyone initially thought, leading to a different kind of relationship between the human and the monsters.
One plot idea could be that they discover their brotherhood early on and train together more closely. They might combine their unique abilities, like Naruto's Rasengan and Sasuke's Chidori, to create new and powerful jutsus. This could change the whole dynamic of the story, with them facing challenges as a united front instead of rivals.
One idea could be that Naruto's dragon summon is a powerful and ancient being. It could help Naruto in battles against extremely strong foes like Madara or Kaguya. For example, the dragon might have unique abilities like breathing fire that can melt through powerful jutsu defenses. Another plot idea is that the dragon has a connection to Naruto's Uzumaki heritage, perhaps it was once an ally of the Uzumaki clan long ago. And the dragon could also teach Naruto new and powerful techniques that are related to dragon - like chakra control or flying abilities, which would give Naruto an edge in his ninja adventures.
Maybe the chameleon is from a long - lost clan of summon animals that were thought to be extinct. And it holds the key to a powerful jutsu that was lost in time. Naruto discovers this when he first summons the chameleon and has to go on a journey to unlock the jutsu's potential.