One idea could be a young ninja discovers an ancient and forgotten monster summoning contract. He then has to figure out how to use it without proper training, leading to some comical and dangerous situations. For example, he might accidentally summon a really small and useless monster at first, but over time, learns to summon more powerful ones.
Another plot could be that there are multiple summoning contracts hidden in different parts of the ninja world. The characters embark on a quest to find all of them. Along the way, they face rival ninja groups who also want the contracts for their own power - up. This could lead to epic battles and alliances being formed.
Perhaps the summoning contract is cursed. In the fanfiction, the main character Naruto (or another character) signs the contract thinking it will give him an edge in battles. But instead, it starts to bring bad luck. Every time he summons a monster, something goes horribly wrong in his village. So he has to find a way to break the curse before it's too late.
In some 'naruto cobra summoning contract fanfiction', there could be a story where the cobra summons are connected to an old prophecy. The protagonist, by signing the contract, is thrust into a journey to fulfill this prophecy. They might have to overcome internal and external obstacles, like dealing with other ninja clans who are jealous of their new power and also understanding the true meaning of the prophecy which is hidden in the cobra's lore.
Well, perhaps in the fanfiction, the female Naruto is an outcast in the village because of her dragon summoning contract. The village elders fear the power of the dragons. So, she has to train in secret with her dragon summons. They could go on adventures to different elemental lands to gain more power and knowledge. Along the way, she befriends other outcasts who also have unique abilities. And when the village is in real danger, she shows up with her dragon army to save the day.
One idea could be a story where a young and inexperienced ninja discovers an ancient slug summoning contract. They initially struggle to communicate with the slugs but gradually form a deep bond. Maybe they use the slugs' unique abilities, like their healing powers, in unexpected ways during battles.
A great fanfiction concept could be centered around a group of rogue ninjas who steal the snake summoning contract. They use the summoned snakes for their evil deeds, causing chaos in the ninja world. A young, inexperienced ninja team is then tasked with retrieving the contract. Along the way, they learn about the history and power of the snake summonings, and they also face moral dilemmas when they realize some of the snakes are not as evil as they seem.
One idea could be that the lizard has a unique ability like being able to camouflage in any environment, which helps Naruto in a stealth mission. Maybe the lizard can also communicate with other reptiles and gather information for Naruto.
Well, perhaps the jaguar summon is from a long - lost clan's summoning contract. Naruto is the first in a long time to be able to summon it. The jaguar could have a connection to an ancient power that Naruto has to learn to control. For example, it might be able to enhance Naruto's chakra in a unique way that he has to figure out through trial and error.
One idea could be that Naruto discovers a new type of shark summon that has special powers. For example, it can swim through the earth as if it were water, allowing Naruto to use it in unexpected battle situations. Another plot could involve Naruto's shark summons having a connection to an ancient underwater civilization. This could lead to adventures where he has to protect the secrets of this civilization from enemies who want to use it for their own gain.
One interesting plot idea could be that Naruto discovers a hidden jutsu that allows him to summon Pokemon instead of the usual toads or snakes. He might start by summoning a Pikachu, and they form an unlikely bond. Pikachu could teach Naruto about electric - based attacks that he could incorporate into his ninja skills.
Well, in some fanfictions, the hellhound summoning contract could lead to a whole new set of adventures. The hellhounds might have their own society or hierarchy, and the main character has to navigate through that while also dealing with the normal Naruto - type challenges like fighting other ninja clans or protecting their village.
One idea could be Naruto summoning a fox with unique abilities, like a fox that can control time for a short period during battles. Another could be a story where the summoned fox has a connection to an ancient prophecy. Maybe the fox is the key to unlocking a hidden power within Naruto that has been lost for centuries.