One idea could be that Naruto discovers a hidden land where tigers and dragons coexist. He has to learn their ways to gain a new power. Another could be a dragon and a tiger are in a feud, and Naruto has to mediate between them using his ninja skills.
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.
One plot idea could be that Naruto discovers a female dragon in a hidden forest. The dragon is injured and Naruto uses his healing abilities to help her. In return, the dragon offers to teach Naruto a special form of chakra control that only dragons know. Another idea is that the female dragon is being hunted by a group of rogue ninjas for her scales. Naruto decides to protect her and they form a bond during the battles against the hunters.
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.
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.
One plot idea could be that the main character, who has the dragon bloodline, teams up with Anko to face a new and powerful enemy in the Naruto world. This enemy could be after the power of the dragon bloodline.