A cool plot idea is that the OC team gets involved in a mystery where ninja from different villages are being attacked by an unknown force using a strange new jutsu. They have to team up with some of their rivals from other teams to solve the mystery. Or perhaps the OC team stumbles upon a prophecy that foretells their role in a great battle that will decide the fate of the ninja world, but they first have to prove themselves worthy.
You could have a plot where the OC team is sent on a mission to a small, war - torn village. Their task is to help the village rebuild and train its new generation of ninjas. Along the way, they face challenges from local bandits and also from a corrupt ninja who wants to take over the village for his own gain. As they struggle to protect the village, they learn valuable lessons about friendship, loyalty, and the true meaning of being a ninja.
One idea could be that your OC team is assigned a special mission to explore an ancient, forgotten ninja temple. Inside, they discover a powerful and dangerous jutsu that other villages are also after. Another is that they have to protect a visiting diplomat from another ninja village who has a secret that could change the balance of power in the ninja world.
One idea could be that the OC team is on a mission to retrieve a rare and powerful ninja artifact that has been lost for centuries. This could lead to battles with other ninja clans who also want the artifact.
One idea could be that the OC team is on a mission to retrieve a powerful relic lost in a dangerous, abandoned Grimm-infested city. Each member of the team has a unique skill that they have to use to overcome different obstacles, like one being able to manipulate ice to freeze the Grimm, another with super speed to outrun them, etc.
One idea could be that Team 7 has to protect Naruto from a new and powerful enemy who can manipulate time. They must constantly be on guard as this enemy tries to go back in time to kill Naruto when he was a child. Another could be that they protect Naruto from a dark curse that was placed on him by an ancient clan. They search for a way to break the curse while fending off those who want to use the curse for their own evil purposes.
A possible plot is that the cat OC is a magical being from a different dimension. It gets lost in the Naruto universe and Naruto helps it. In return, the cat OC teaches Naruto some unique chakra - control techniques that it has from its own world, which gives Naruto an edge in battles.
One idea could be an OC who is a master of a unique water jutsu in Kirigakure. They could be on a mission to uncover a long - lost secret about the village's founding. Another could be an OC who is trying to reform Kirigakure's harsh shinobi training system from within. Maybe an OC with a special bloodline limit that is feared by others in the village at first but then they prove their worth.
One idea could be a fanfic where Team Naruto goes on a mission to a hidden, magical forest that has the power to bring out their deepest fears and they have to overcome them to complete the mission. Another could be a story where they time - travel back to the days of the First Hokage and get involved in the early battles and politics of Konoha. Maybe a fanfic where they have to team up with their enemies from past missions to fight a common, greater evil that threatens the entire ninja world.
One interesting plot idea could be that during training, Naruto discovers a new jutsu on his own. He might be trying to perfect his Rasengan and accidentally combines it with his shadow clone technique in a unique way. This new jutsu could give Team 7 an edge in future battles.
One idea could be an OC who has a unique jutsu that helps Team Minato in a difficult mission. For example, an OC with the ability to control time briefly. This could create exciting scenarios where they can turn the tide of battle against a powerful enemy.
In a 'naruto solo team fanfic', Naruto could be sent on a diplomatic mission alone. Since he's known for his ability to make friends, the village elders think he can handle it. He meets different ninja clans and has to convince them to form an alliance with Konoha. Without his team, he has to rely on his own charm and wits. He tells them stories of his past battles and how Konoha has always been about peace and unity. Along the way, he also discovers some secrets about the clans that could be beneficial for Konoha in the future.
A mystery - themed 'the oc fanfic' would also be great. Maybe there's a mystery surrounding the Cohen family's wealth or a long - lost relative that suddenly shows up with a hidden agenda. The characters would have to work together to solve the mystery, and in the process, their relationships would be tested and new alliances formed.