One possible plot could be that Naruto and Sakura, after getting married, are somehow sent back in time to their early days at the ninja academy. They have to navigate their past selves while also trying to figure out a way back to their own time. Naruto might use his knowledge of future events to prevent some tragedies, and Sakura could use her medical skills in new ways in the past.
Their relationship would likely be more complex in the past. Since they are from the future and already married, they would have a deeper connection. But they would also have to hide it from their past selves. Naruto might be more protective of Sakura in the past, and Sakura would be more confident in their relationship.
One great Sasuke, Naruto, and Sakura time travel fanfiction is 'Time - Twisted Bonds'. In this story, they are sent back to their childhood days with their present - day knowledge. It's really interesting to see how they interact with their younger selves and try to change things for the better. Another good one is 'Journey Through Time' where they travel to different points in the Naruto timeline and face challenges that were not part of the original story.
There's 'Time - Twisted Destiny' too. In this fanfiction, when Naruto and Sakura travel back in time, they find themselves in a situation where they have to be very careful not to disrupt the timeline too much. Their interactions with younger versions of their friends are really fun to read. The story also delves deep into Sakura's growth as she tries to use her medical skills in a more impactful way in the past.
Naruto, of course. Since they are in the same team in the original story, it's very likely that Sakura will interact with Naruto. She might try to change his fate or help him in a different way. Sasuke is also a main character she'll interact with. Maybe she'll try to prevent Sasuke from going down his dark path. And Kakashi, as their teacher, will also be involved in their interactions.
In a Sakura and Kakashi time travel fanfiction, they could end up in the past during a major war. Kakashi would be a great asset with his Sharingan and combat skills. Sakura, on the other hand, could help the wounded soldiers. Their presence in the past could change the outcome of the war. For example, they might be able to save some important characters who were supposed to die. This would then lead to a completely different future when they return to their own time.
During time travel, Naruto might see Sasuke in a different light as they face historical events. Sasuke could also start to respect Naruto's leadership more. And Sakura, with her skills, would be more of an equal in their group. This could lead to a more balanced and harmonious relationship among the three. For example, in a time when they have to deal with a powerful enemy from the past, they'd have to trust each other completely, which would deepen their bond.
One interesting plot could be Sakura traveling back in time and using her modern medical knowledge to save characters who previously died in the original Naruto story. For example, she might be able to prevent the death of Minato, which could have a huge impact on the entire Naruto world. Another plot could be Sakura trying to change Naruto's childhood by being there for him earlier and preventing some of the bullying he endured. This could lead to a different Naruto, perhaps more confident from the start.
A common theme is dealing with the consequences of time travel. They can't just change things willy - nilly without consequences. In many fanfictions, they have to carefully consider their actions because any small change could have a huge impact on the future. And there's also the theme of nostalgia. Returning to the past brings back memories and emotions, and they often have to deal with how they feel about their past selves and the events that happened back then.
One interesting story could be where Naruto and Sakura travel back to the time when the Uchiha clan was still intact. They try to prevent the massacre. Naruto might use his talk - no - jutsu to convince Itachi and the elders to find a different solution. Sakura could use her medical skills to help the sick in the clan, thus changing the course of the whole Naruto storyline.