In the fanfiction, when Kirito turns into a girl, it could be that she discovers new abilities or powers that are only accessible to female avatars in the game world. This could lead to her being sought after by different factions in the game. She might also struggle with her own identity, torn between her original male self and the new female form she has to adapt to in this virtual realm.
Well, perhaps the story could revolve around Kirito's relationships. As a girl, his/her interactions with Asuna could change significantly. They might develop a different kind of friendship or even a romantic relationship that has new dynamics compared to when Kirito was male. Also, other characters like Klein might react in very interesting ways to this transformation.
Well, one possible plot could be that Kirito, now as a girl, has to deal with different social interactions. For example, other characters who were used to his male self might be shocked at first. He would have to adapt to new ways of being treated in the virtual world of SAO. Maybe some characters who were just friends before start to develop different kinds of feelings for this new female version of Kirito.
The other characters' reactions would be quite diverse. For the more competitive male players, they might see this as an advantage or a disadvantage depending on their relationship with Kirito. If they were rivals, they might think it's a chance to outdo him now that he's a girl. But if they were friends, they would offer support. Female characters like Silica might be excited to have another girl around and might start sharing girl - only things with Kirito. The guild members of Kirito's previous guilds would likely be confused but still accept him, after all, they know it's still Kirito inside.
A possible plot twist could be that Kirito, as a girl, is actually a princess in the real world who is using the virtual world to escape from her royal duties. This would completely change the way other characters view her and add a lot of mystery and intrigue to the story.
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.
In a 'Robin turns into a girl fanfiction', perhaps there's a magic spell gone wrong that causes the transformation. Robin then has to find a way to reverse it. Along the way, he might form new relationships or face challenges in his existing ones. For example, his romantic interests could change or be put to the test.
Perhaps the plot starts with some kind of magic spell or experiment gone wrong that turns Markiplier into a girl. As a girl, he could discover new aspects of his personality. He might find that he has more empathy or different interests. And his fans would have all kinds of reactions, some being really supportive and others being quite shocked. He'd also have to deal with the physical changes, like getting used to different clothing styles and body language.
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 the story could start with Keith being exposed to a strange energy. This energy alters his DNA, turning him into a girl. As a girl, he finds that he's now treated differently in society. He uses this experience to understand the struggles that girls face. He might also have to adapt to physical changes like different body strength and new ways of expressing emotions.
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, one possible plot could be that Hiccup accidentally drinks a magic potion made by a mischievous wizard. As a girl, he (now she) has to deal with the different reactions of the people in Berk. Some are shocked, some are curious. And she has to learn how to adapt to the new body while still maintaining her heroic spirit, facing the same dragons but in a different physical form.