Perhaps a fanfiction where Tsubasa time - travels back to the early days of football in Japan. He meets the pioneers of the sport in his country and uses his modern skills and knowledge to inspire them and help develop the game even faster than it actually did. He could also face challenges in this different era, like dealing with more primitive equipment and different rules interpretations.
One idea could be a story where Sanae is a huge supporter of Captain Tsubasa's football career. She could be the one who encourages him during tough times, like when he has an injury or is facing a difficult opponent. This would add an interesting dynamic to the story as she provides emotional support from the sidelines.
Well, perhaps a plot where they are transported back in time to an era when magic was first discovered. They have to learn how magic was initially harnessed and face challenges from the past. They could also find out secrets about their own families or the origin of their magic. This would involve a lot of exploration and discovery for both of them, and they would need to support each other through it all.
Well, they could be transported to a modern - day Earth and have to adapt to a completely different culture while still maintaining their relationship. It would be funny to see them deal with things like smartphones and cars.
It's an exciting story about football and the growth of the characters. The plot focuses on their challenges and achievements on the field.
One plot idea could be an OC who is a scientist during World War II and teams up with Captain America. They could work on some top - secret projects together. Another is an OC who is a foreign agent sent to assess Captain America's abilities and ends up becoming his ally. Maybe an OC from the future who travels back in time to help Captain America prevent a major catastrophe that wasn't in the original timeline.
One idea could be exploring the backstory of the captain before the promise was made. Maybe there was a tragic event in their past that led them to make such a solemn vow. Another could be a situation where the captain has to break the promise to save their crew, and then deal with the moral and emotional consequences.
One plot idea could be that Tinkerbell is sent on a mission by the fairies to steal a magical item from Captain Hook. But during the process, she discovers that Hook has a tragic past that led him to his villainous ways. This makes her question whether he's truly all bad.
One idea could be Captain Marvel bringing back some alien tech that the Avengers have to figure out how to use. It could lead to new powers for some of the members or a new way to defend Earth.
One idea could be a crossover where the Naruto characters interact with the Shinigami captains in a battle against a common enemy. For example, Naruto's unique jutsu combined with a Shinigami captain's zanpakuto abilities would make for some epic fight scenes.
Another idea is that there's a villain who can manipulate time and space. He sends Captain America to the Naruto world during a crucial time in Naruto's story, like right before a big battle. Captain America's leadership and battle experience help Naruto and his friends come up with a better strategy. And in the process, they learn from each other's values and fighting styles.