A simple plot could be that a powerful witch casts a spell on him during a battle. As a girl, he could struggle with his self - image at first. For example, he might be worried about how his father, Death, will react. Then he realizes that he can use this new form to his advantage, like infiltrating a witch's lair where only females are allowed.
One idea could be that Kuroko turns into a girl due to a magical experiment gone wrong. His friends are initially shocked but then start to see the new 'her' as just Kuroko with a different appearance. Maybe there could be a plot where 'she' has to adapt to the different treatment from others in the basketball team, like some being overly protective or others being a bit awkward around 'her'.
Well, in a fanfiction where Peter Parker turns into a kid, perhaps he could end up at his old school. He'd be faced with bullies again, but this time he has the knowledge and experience of being Spider - Man, even if he's in a kid's body. This could lead to some interesting scenarios where he uses his smarts to outwit the bullies without using his powers directly. Or, he could befriend his younger self's friends in a whole new way, seeing them from a different perspective.
One plot idea could be that Inuyasha, as a girl, has to deal with different reactions from the other characters. For example, Miroku might be more hesitant to touch her inappropriately as he used to do sometimes with Inuyasha in his male form. Kagome could be both confused and intrigued, and they might have to re - evaluate their relationship. Another idea is that Inuyasha in female form has different powers or a different way of using her existing powers, which leads to new adventures and challenges in fighting demons.
Maybe in this fanfiction, Midoriya as a girl discovers new aspects of her power. Since her body has changed, the way she channels her quirk might also be different. She could then have to train all over again to master this new way of using her ability.
Perhaps in a parallel universe, Superman is born as a girl. This version of her grows up with different experiences and challenges. She could be more in tune with female issues in society and use her powers to fight for gender equality as well as the usual superhero stuff like saving the world from villains and disasters.
Another possibility is that Finn - now a girl - discovers new powers or abilities that were hidden before. Since in many stories, a change in gender can sometimes bring out different aspects of a character. She could use these newfound powers to fight against the villains in Ooo in a more creative way than before.
Well, a possible plot could be Sasuke's transformation into a girl is part of a powerful jutsu gone wrong. As a girl, she has to find a way to reverse it. In this process, she might discover new aspects of her own abilities or weaknesses. Also, there could be a plot where she has to prove herself in battles all over again, since some might underestimate her as a girl.
One idea could be that Dean, as a girl, has to navigate the same dangerous situations but with a different set of challenges due to his new gender. For example, he might face different reactions from male characters who underestimated him before. Another could be exploring his relationships, like how his friendship with Sam might change, with Sam having to protect 'her' in a different way. And perhaps there could be a plot where 'female Dean' has to use her newfound charm to get information in a case in a way that male Dean couldn't have.
One idea could be that Link, as a girl, has to face different challenges in Hyrule. Maybe the other characters initially don't recognize her and she has to prove herself all over again. Another could be that she uses her new form to infiltrate an all - female group that holds a key to saving the kingdom.
In a fantasy world, a boy is cursed by an evil witch to turn into a girl. To break the curse, he has to complete a series of quests. Along the way, he meets different characters who teach him about the different experiences and challenges that girls face, and he gains a new understanding and respect for the opposite gender.