Well, one possible plot could be that Yugi turns into a girl due to a magical spell gone wrong. Then he/she has to deal with the new identity while still being involved in his usual card games. Maybe the other characters are initially shocked but then gradually accept the new Yugi.
One possible plot could be that Yugi, after awakening as a girl, has to face new challenges in the Duel Monsters world. For example, some opponents might underestimate her, but she uses her strategic mind to prove them wrong. She could also form new relationships with the other characters, like a different kind of friendship with Joey or a more complex dynamic with Kaiba.
One idea could be that as a girl, Yugi gets involved in a different kind of Duel Monsters tournament. Maybe she uses her wits and a more feminine charm to outwit her opponents. For example, she could form special bonds with her cards that are different from the male Yugi's connection, like having a more nurturing relationship with her monster cards.
Well, perhaps the plot could involve Yugi adjusting to life in a female body. She might face challenges in how others perceive her now. For example, her friends could initially be shocked and confused. Then, she could use this new form to her advantage in duels, like using the element of surprise against opponents who underestimate her because she's a girl.
One possible plot could be that Yugi wakes up one day as a girl and has to deal with the shock and confusion. His friends might be initially startled but then accept him/her. He/She could then face new challenges in dueling as a girl, like opponents underestimating her.
A possible plot could focus on how Tails' daily life changes. As a girl, she might have to deal with different social expectations. Her hobbies and interests could shift slightly. For example, she might be more interested in certain types of fashion or more nurturing activities. Her relationship with Amy could also change, perhaps they become closer friends as they share more 'girly' things. And Tails' mechanical skills might be seen in a new light, as she uses them in a different way to solve problems in her new form.
Well, one possible plot could be that Sans somehow gets hit by a strange magic spell. As a girl, he/she might struggle to fit into the existing relationships in the Underground. For example, Papyrus might be really confused at first but then tries to be supportive. And Sans (as a girl) could also have different interactions with Frisk, like maybe a more motherly or sisterly bond.
Well, perhaps in the fanfiction, Ash is exposed to a mysterious Pokémon's special ability that causes the transformation. As a girl, Ash discovers new aspects of himself. He might find that some Pokémon are more attracted to his new form and are more willing to be caught or trained. He could also use this new identity to his advantage in battles, like using the element of surprise against opponents who are used to facing the male Ash.
In a fanfiction where Nagisa turns into a girl, it could be part of a wish - fulfillment scenario. Nagisa secretly wished to experience life as a girl for a day, and some supernatural being grants that wish. As a girl, Nagisa has to navigate through daily life, school, and social situations. There could be humorous moments when Nagisa tries to act like a girl but still has some of the old habits from being a boy, like being too rough during sports in a girl's body.
Well, in a Todoroki turns into a girl fanfiction, perhaps there's a villain who has a transformation quirk and uses it on Todoroki as a form of psychological warfare. Todoroki, now a girl, has to find a way to reverse the effect. In the process, he/she realizes that society treats female heroes differently and has to fight against those prejudices too. Maybe he/she even uses this new form to her advantage in some battles, by using the element of surprise.
One possible plot could be that Cloud, after turning into a girl, has to adapt to a world that now views her differently. Maybe she struggles with newfound emotions and social expectations. For example, she might have been a tough warrior as a male, but as a girl, people underestimate her. She then has to prove herself all over again in battles or quests, while also dealing with her own internal confusion about her new identity.