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 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.
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.
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.
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.
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 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'.
Another idea is that Stein, being the scientist he is, discovers something unusual about Death the Kid's soul wavelengths. This could lead to a story where he tries to study it further, but Kid is initially hesitant because he's worried about the implications. It could explore themes of trust and the pursuit of knowledge.
One plot idea could be exploring how his OCD tendencies start to develop even as a baby. Maybe he gets really fussy if things around him aren't symmetrical, like his crib toys. Another could be about his early interactions with his father, Shinigami. Since Shinigami is such an unusual figure, their father - son moments could be filled with comical misunderstandings as Kid tries to figure out his dad. Also, a plot could involve Kid's first encounters with the other characters in the Soul Eater world as a baby, like how he might react to Maka and Soul when they come to visit.
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 idea could be a story where Death the Kid has to team up with a character from Soul Eater to face a new, powerful enemy that threatens the balance between the world of humans and the world of demons. They might start off not getting along due to their different personalities and ways of doing things, but as they face challenges together, they learn to respect each other and combine their strengths to defeat the foe.