One idea could be that the daughter of an Anbu member is discovered to have a unique Kekkei Genkai. This leads to her being closely watched by the Hokage, Naruto in this case. Maybe she has the power to manipulate time on a small scale, which could create all sorts of interesting scenarios in the ninja world. For example, she could use it to prevent small disasters or help in battles without others realizing how she's doing it at first.
Perhaps the Anbu daughter has a special bond with a tailed beast. Since Naruto has his own experience with the Nine - Tails, he takes an interest in her situation. She could be the key to a new form of power that combines human and tailed - beast chakra in a unique way. This might lead to her being targeted by enemies, and Naruto has to protect her while she learns to control this new power.
Perhaps in the fanfiction, there's a prophecy that only Hokage Naruto and Anbu Sasuke can fulfill together. They have to embark on a dangerous journey outside the village to prevent a great disaster. Along the way, they face many challenges that test their friendship and skills. For instance, they might have to fight against ancient and powerful creatures. This would not only show their combat abilities but also how they support each other in difficult situations.
One idea could be Sasuke leading an Anbu mission while Naruto, as Hokage, has to deal with the political fallout of the mission's actions. For example, if the Anbu under Sasuke's command accidentally cross a border during a pursuit, Naruto has to smooth things over with the neighboring village.
Another plot could be set after Naruto becomes Hokage. Itachi somehow returns or his past actions are re - examined in a new light. Naruto, as the Hokage, has to deal with the revelations about Itachi and how they impact the village's history and relationships. They might work together to heal old wounds and face new challenges that are related to the past secrets of the Uchiha clan.
One idea could be that she struggles with the pressure of living up to her father's legacy as Hokage. Maybe she has to deal with villains who target her specifically because of who her father is. Another could be her journey to discover her own unique ninja way that's different from her father's.
One idea could be a story where Naruto has to face a new, powerful and mysterious enemy that has the ability to manipulate time. This would put his skills as a Hokage to the ultimate test.
One idea could be exploring the Shodai Hokage's early days as a ninja, before the founding of the village. Maybe show his training and how he developed his unique skills.
One idea could be Naruto having to deal with a new and powerful enemy while still adjusting to his role as the 5th Hokage. Maybe this enemy has a unique jutsu that can disrupt the village's chakra network. Another idea is Naruto using his new position to reform the shinobi education system in the village. He could introduce new training methods that focus on teamwork and moral values as well as combat skills.
One idea could be Naruto as Hokage facing a new threat that only Hinata's unique skills can help with. For example, a mysterious enemy that can nullify normal ninjutsu, but Hinata's Byakugan - based techniques are effective. Another plot could be a time - travel fanfic where Naruto and Hinata go back in time and have to prevent a disaster that would change the future of the Hidden Leaf Village. They could also explore their relationship in a different era.
One idea could be that Sakura becomes Hokage first. Naruto goes on a long-term mission and during his absence, Sakura steps up and proves herself as a great leader. She implements new medical ninja programs in the village. When Naruto returns, he is proud of her and they work together to make the village even better.
One idea could be Naruto and Sasuke teaming up to face a new, powerful and ancient threat that even the combined might of the Hidden Villages can't handle easily. They have to use their unique skills and the bond they've reforged as Hokage and his equal.