One idea could be that Minato and Kushina travel back to the time when the Hidden Leaf Village was first founded. They could use their modern - day knowledge and skills to help shape the village in new ways, like introducing new jutsu training methods. Another could be that they go back to a time when a great war was about to start and they use their powers to prevent it, thus changing the future of the ninja world.
One plot idea could be their first meeting. Maybe Minato saves Kushina from some bullies in the ninja academy. It could show how their initial attraction starts. Another idea is a mission they go on together. They face challenges and have to rely on each other's skills, which deepens their bond. A third plot could be about them preparing for their wedding. They deal with the stress of family expectations and also the joy of starting a new life together.
One idea could be that fem Naruto travels back in time and has to hide her identity from Minato at first. She could then gradually reveal herself and use her future knowledge to help Minato prevent some of the tragedies that occurred in the original timeline. For example, she might know about certain Orochimaru plots and stop them before they start.
One idea could be that Naruto travels back in time and tries to save Kushina from her tragic fate. In the process, he accidentally creates a harem situation where various characters are attracted to him due to his future knowledge and his determination to change things. Another plot could involve Naruto using his time - traveling abilities to prevent certain events that led to the chaos in the ninja world, and as he does so, he forms deep bonds with different characters, including those in Kushina's circle, which gradually turns into a harem - like scenario.
One idea could be exploring how Kushina and Minato's relationship influenced Naruto's growth. For example, in the fanfic, Naruto could discover old letters from his parents that reveal their hopes and dreams for him. This would add an emotional depth to his character.
One idea could be that they travel back to a crucial moment in the history of the ninja world and change some small events that end up having a huge impact on the future. For example, they prevent a certain battle from happening too early, which gives the ninja villages more time to prepare for a bigger threat that was coming later.
In some 'naruto and kushina time travel fanfiction', a cool plot point is Naruto and Kushina teaming up in the past. They could use their combined skills to change certain events. For example, they might be able to prevent some of the tragedies that occurred in the original story, like the Uchiha massacre. Naruto could use his knowledge from the future, and Kushina with her strong chakra, would be a great duo.
It could be a rogue ninja from the future who follows them back in time. This ninja might have some vendetta against Minato or Kushina or wants to change the past for his own evil purposes. Maybe he wants to prevent Minato from becoming the Fourth Hokage so that he can take over the village in the future.
A fanfiction could center around a family training session. Minato trains Naruto in advanced ninjutsu techniques while Kushina teaches him about the Uzumaki clan's secrets. This would not only strengthen their family bond but also make Naruto an even more powerful ninja.
Well, perhaps a plot twist is that when they time travel, they end up switching bodies. Naruto, in Minato's body, has to deal with the responsibilities of being a Hokage in the past, while Minato, in Naruto's body, has to navigate through Naruto's life in the present. This would create a lot of comical and also very tense situations as they both try to adapt and not mess up the timeline.
One interesting plot twist is if they time travel and find that the world they end up in has a different version of the Chakra system. They have to adapt quickly to this new form of energy while also trying to find a way back home. Also, imagine if they time travel and discover that Naruto was supposed to be born in a different village in this alternate timeline. This would completely change the way they view Naruto's destiny and their role in protecting him.