In the fanfiction, perhaps Wonder Woman is trapped in some sort of magical or technological prison created by an enemy. Batman, with his detective skills, figures out how to break in and free her. He might have to solve a series of puzzles or overcome various security measures. He then rescues her and they team up to take on the bad guy who imprisoned her.
One possible plot could be that Wonder Woman gets trapped in a dimension where her powers are nullified and Naruto, with his ninja skills and chakra, somehow enters that dimension. He uses his shadow clone jutsu to create distractions for the enemies while he figures out a way to restore Wonder Woman's powers. Then, they team up to fight the common foe that had trapped her in the first place.
In this fanfiction, the story could start with Wonder Woman being intrigued by the tales of Batman she hears from other heroes. She decides to visit Gotham to see for herself. Batman, on the other hand, is initially skeptical of this powerful and otherworldly being in his city. However, as they start to interact, they find that they share a common goal of protecting the innocent. They might face a powerful criminal organization that is using advanced technology and magic. Wonder Woman's super strength and combat skills along with Batman's gadgets and strategic mind would make for an exciting story as they battle the bad guys together.
The plot might involve an alternate universe where Batman and Wonder Woman are not part of the traditional Justice League setup. They meet in a more normal, civilian - like situation. Batman could be investigating a crime that has ties to Wonder Woman's past. As they dig deeper into the mystery, they rely on each other more and more. Their mutual respect turns into attraction. Wonder Woman is attracted to Batman's intelligence and tenacity, while Batman is drawn to Wonder Woman's power and noble heart. Eventually, they fall in love while still trying to solve the mystery that brought them together.
In such a fanfiction, the plot could involve Batman realizing his deep love for Wonder Woman over time. Maybe he plans an elaborate proposal during a lull in their crime - fighting adventures. He might choose a location that holds special meaning for them, like the rooftop where they first teamed up to take down a powerful villain.
One possible plot could be that Wonder Woman and Batman have been working together for a while in the Justice League. As they grow closer, Wonder Woman develops deep feelings for Batman. She notices that Batman is always in dangerous situations and there are other women around him in Gotham. So, she becomes possessive, trying to keep him closer to her side. This causes some tension in their relationship as Batman is used to his independence, but also starts to see Wonder Woman in a new light.
Darkseid is another possibility. He's a powerful and menacing villain. If he sets his sights on Wonder Woman, Batman would be forced to act. He'd need to use all of his skills and resources to save her from Darkseid's Omega Beams and his army of minions.
Well, it could start with a gala event where all the superheroes are present. Batman and Wonder Woman are paired for a dance, and there's an instant spark. They decide to go on a proper date. Their date might be a flight together over the city, with Wonder Woman carrying Batman. As they date, they start to influence each other. Batman becomes a bit more open and less brooding, while Wonder Woman learns some of Batman's detective skills. But then, they have to deal with public opinion within the superhero community, some of whom think they should focus only on their duties.
In this batman and wonder woman school fanfiction, the school could be a special academy for meta - humans. Batman and Wonder Woman are there to recruit the best students for a new superhero team. However, there is a rift between the students who idolize Batman's more brooding and stealthy approach and those who prefer Wonder Woman's open and powerful style. This causes conflicts within the school. But when an outside threat arrives, they all have to come together under the guidance of Batman and Wonder Woman to protect the school and prove that different styles can work together for a common good.
One possible plot could be that Batman, due to his brooding nature and fear of getting too close, does something that shatters Wonder Woman's heart. Maybe he lies to her about his true feelings or betrays her trust in some way related to their superhero duties.
One possible plot could be that Batman and Wonder Woman are in Vegas on a mission. Maybe they are tracking a villain who is using the glitz and glamour of Vegas to cover up some illegal activities, like money laundering through the casinos. They start by infiltrating the casinos, with Wonder Woman using her charm and Batman his detective skills. Along the way, they might have some misunderstandings due to their different approaches but in the end, they work together to take down the bad guys.