One idea could be that Naruto, as a dragon, has to protect the Hidden Leaf Village from a new threat that is specifically targeting dragons. He could use his dragon abilities like flight and powerful breath attacks to fend off enemies.
Another plot could be that Naruto is turned into a dragon as part of a curse by an evil sorcerer. He has to find a way to break the curse while still being a dragon. As a dragon, he might face discrimination from some villagers who are afraid of him, but his friends would stand by him. He would then embark on a journey to find the sorcerer and force him to remove the curse.
Maybe Naruto, in his dragon form, discovers a hidden dragon realm and has to learn about his new identity and powers there. He could meet other dragon characters and form alliances, all while trying to figure out how this new form relates to his ninja skills. He might even bring some of the dragon knowledge back to the Hidden Leaf to make it stronger.
One idea could be a young Naruto discovers an ancient scroll that allows him to summon dragons instead of toads. He then has to train with these dragons to master new jutsus. Another could be that the dragon summons are from a different dimension and bring with them a new type of chakra that Naruto has to learn to control.
One idea could be that Naruto uses the Dragon Henge to infiltrate a secret organization that has a dragon as its symbol. He could gather intelligence while in the form of a dragon.
Perhaps in the fanfiction, the dragon soal (soul) is a key to unlocking an ancient prophecy. Naruto, being the main character, has to go on a journey to understand the dragon's power and how it relates to the future of the ninja villages. He might face challenges from those who want to use the dragon's power for evil.
One plot idea could be that the dragon girl is from a hidden land and she comes to the Ninja World. Naruto, being curious, befriends her. They could go on adventures together, like finding a powerful ancient scroll that is said to hold the secrets of both their worlds. Another idea is that the dragon girl has a special power that is needed to stop an upcoming evil in the Ninja World, and Naruto helps her harness and control it.
One idea could be that Naruto discovers a hidden dragon summoning scroll. He tries to master the summoning technique, but the dragons are very powerful and difficult to control at first. Another plot could involve a dragon that has a special connection to Naruto's family history. Maybe his mother or father had a pact with the dragons long ago.
One idea could be Naruto using his dragon to quickly travel across the ninja world for missions. His dragon could also have unique abilities, like breathing a special type of chakra-infused fire that can counteract certain jutsu.
One idea could be that Naruto discovers a hidden power within himself that has a connection to the F Dragon. Maybe the F Dragon is a guardian of an ancient ninja art, and Naruto has to prove himself worthy to learn it. Another plot could involve Naruto and the F Dragon teaming up to fight a common enemy that threatens both the ninja world and the dragon's realm.
A cool plot might be where the dragon summoner is initially feared by the villagers because of their strange power. But as time goes on, they prove that the dragon can be a force for good. They could then team up with Naruto and his friends to fight against a new threat that normal ninjutsu can't handle. For example, a group of powerful rogue ninjas who have some sort of anti - ninjutsu abilities, and only the dragon's magic - like powers can defeat them.
In this fanfiction, it could be that the Red Dragon Emperor's abilities are mistaken for a new and dangerous form of jutsu. This misunderstanding might lead to Naruto being hunted by certain groups within the ninja world who fear this unknown power. Meanwhile, Naruto has to figure out how to use this power to protect his friends and village, and also how to clear the misunderstandings.
Maybe the Wood Dragon Slayer has a connection to the Sage of Six Paths. This connection gives them unique abilities that no one else has. They could discover this connection during a dangerous mission in an ancient ruin. And then they have to learn how to control these newfound powers while also dealing with the political unrest in the village that arises from others fearing their new strength.