One idea could be an OC Hatake who has a unique chakra ability. For example, they can manipulate ice in a way that's different from Haku. They could use this to create ice sculptures that come to life in battle. Another plot could involve the OC Hatake being a long - lost relative of Kakashi. This would bring in a lot of family - related drama and secrets to uncover. A third idea is that the OC Hatake has a special bond with animals, like being able to communicate with wolves, which is rare in the Naruto universe.
One idea could be that Hatake Kakashi somehow transfers his Sharingan to Naruto in a dangerous mission. This would give Naruto new abilities and a whole new set of challenges to face. He'd have to learn to control the Sharingan quickly while also dealing with the enemies who might target him specifically for it.
Maybe an OC from a different village who is sent on a mission with Kakashi. Their different backgrounds and skills create an interesting dynamic during the mission. For example, the OC could be a master of water jutsu and Kakashi has to adapt his combat style to work with them.
One idea could be an OC who is a new ninja in the village and Kakashi becomes their mentor. The fanfic could explore their training sessions and how the OC grows under Kakashi's guidance.
Well, a cool plot might be Kakashi time - traveling to the era of the First Hokage. There, he could learn ancient jutsu and bring them back to his time. Maybe he gets involved in a conflict that was long forgotten but has implications for his present. He could also time travel during a crucial battle in his own past, like the fight against Obito, and change the outcome in unexpected ways.
One idea could be an OC who is a time - traveler from the future. They come back to the Naruto world to prevent a great disaster that they know will occur in the future. This OC could have unique powers related to time manipulation or future - sight.
One idea could be an OC Senju who has a unique ability related to plant manipulation, like being able to make plants grow rapidly into defensive or offensive structures. Another could be an OC Senju who is a healer and has to deal with the aftermath of a big battle in the Naruto world. Maybe an OC Senju who is on a quest to discover a long - lost Senju clan jutsu that was forgotten over time.
One idea could be that the OC is reincarnated as a member of a powerful but long - lost clan in the Naruto world. They then have to discover their clan's secrets and powers while also dealing with the ongoing conflicts in the shinobi world. For example, they might find a unique jutsu that was lost with their clan.
Perhaps the OC is a healer who is the only one who can keep Naruto's body stable when he overuses his Rinnegan. Their relationship starts as a necessity but then develops into a deep friendship or more. They get involved in a conflict where Naruto has to use his Rinnegan to save the OC's clan from destruction, and in the process, they learn more about the secrets of the Rinnegan and their own destinies.
A plot could revolve around a mission where Kakashi and Sakura are paired up alone. They end up in a strange, enchanted forest. Sakura discovers a new type of medicinal plant that has the power to enhance chakra control. Kakashi helps her study it, and in the process, they learn more about each other's dreams and fears. It could also be a story of their friendship growing deeper.
One plot idea could be a time - travel scenario. Sakura somehow gets sent back in time and meets a younger Kakashi. They start off as strangers but as they train together, a bond forms. Another could be a mission - gone - wrong situation where they are stranded in a dangerous place and have to rely on each other for survival, which deepens their relationship. And a third idea is a body - swap situation where they have to understand each other's lives and feelings better while in each other's bodies.