Another theme is the exchange of knowledge. For instance, a character from the past might have some unique skills or knowledge that is valuable in the future, and vice versa. They then share and learn from each other, like an ancient herbalist teaching future doctors about natural remedies that have been forgotten.
One common theme is redemption. Characters from the past might have made mistakes and in the future - set story, they get a chance to make up for it. For example, a character who was once a villain in the past might find a way to redeem themselves in the future. Another theme is the cycle of life. The past and future are often used to show how things come full circle, like how a character's actions in the past lead to consequences in the future that in turn affect the past again. And of course, the power of memory. How memories from the past shape the future and how characters deal with forgotten or recovered memories is also a big part of these fanfictions.
One common theme is self - discovery. When Naruto from the past goes to the future, he often has to re - evaluate who he is in the context of this new world. Another theme is the impact of the past on the future. It shows how the actions and decisions made in the past can have far - reaching consequences.
One idea could be a time - traveling hero from the past who gets stuck in a high - tech future world and has to adapt to new technologies while using his old - fashioned skills to solve problems. For example, a medieval knight in a world of flying cars and laser guns.
One possible plot could be that future Gohan travels back in time to warn the past about an upcoming threat that was not properly dealt with in his own timeline. He might meet the past version of himself and try to train him to be stronger, sharing his knowledge of the future battles. Maybe he also meets the past versions of his friends and family, and has to convince them of the seriousness of the situation without revealing too much about the dark future he comes from.
In 'past meets future' Harry Potter fanfics, a major theme is the clash of different magical cultures. The future might have a more evolved form of magic, and when it meets the past, there are conflicts and also new understandings. Another popular theme is the power of friendship across time. Characters from different time periods form bonds that help them overcome challenges. And then there's the theme of self - discovery. A character going to the past or future might learn something new about themselves that they wouldn't have known otherwise.
A plot where the past and future ninja teams have to compete in a tournament. Each team has their own set of skills and strategies based on their time periods. The past teams might rely more on brute force and basic jutsu, while the future teams have more advanced and unique jutsu. It would be a great opportunity to see the evolution of ninja techniques and how the different generations interact.
One possibility is that future Naruto could give past Naruto some advice on how to handle his relationships better. For example, with Sasuke. He might tell him to be more understanding and patient. Also, future Naruto could show past Naruto some of his new jutsu and inspire him to train harder to reach that level.
One possible plot could be that future Sakura, with her advanced medical skills and battle experience, goes back in time and meets a younger Sasuke. She might try to prevent some of the tragedies that Sasuke later endures. For example, she could warn him about Orochimaru's true intentions, which would change the course of Sasuke's journey. This would also lead to different interactions between Sakura and Sasuke compared to the original story. Their relationship might develop in a more positive way earlier on, as Sakura from the future has a deeper understanding of Sasuke's pain and the consequences of his actions.
Well, they might initially be shocked to see each other. The past Percy could be amazed at how much the future Percy has changed and grown. Maybe the future Percy tries to give the past Percy some advice to avoid future mistakes.
One idea for this 'Past Kakashi Meets Future Obito' fanfiction could be that their meeting is not a coincidence. Maybe it's part of a grand plan by some mysterious force. When they meet, past Kakashi would be in awe of future Obito's power and skills. Future Obito, though, would see the innocence still in past Kakashi. They could end up training together, with future Obito teaching past Kakashi some new jutsu. And as they bond, they might rewrite their fates and change the future of the ninja world for the better.