Perhaps there's a powerful artifact that Gohan touches, and it transforms him into a girl as a form of curse. In this new form, Gohan starts to notice different things about himself and the world around him. He might have to learn new ways to fight and move, as his body is now different. His relationships with his friends like Videl and Piccolo could also change, as they try to help him adapt and find a way to break the curse.
It could be a new villain who is specifically targeting Gohan because of his new form. This villain might see Gohan's transformation as a sign of weakness or an opportunity to mess with the Z - fighters. Maybe they want to use Gohan's confusion and the chaos it causes among his friends and family to their advantage.
If Gohan was a girl, the dynamics within the Dragon Ball universe would shift. Her relationships with other characters might be altered, and her power development could take a unique path.
It could be many characters. Maybe it was Videl. In the Dragon Ball series, Videl is a strong - willed girl, and she has a connection with Gohan. So in the fanfiction, it might be her that Gohan thought was cute.
One possible scenario could be that in this fanfiction, the change forces Kratos to view the world from a different perspective. As a girl, he might face different challenges and reactions from the other characters. Maybe the gods who once feared him now underestimate him, leading to some interesting power dynamics.
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.
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.
Physically, of course, there would be obvious changes. But personality - wise, he might become more in touch with his emotions. In the original, Lelouch was often very calculating and hid his true feelings. As a girl, society in the story might expect her to be more open about her emotions, which could force her to confront and express them more.
I'm not sure specifically as there could be many interpretations. It might be a fan - created story about a girl and Gohan in relation to a red machine. Maybe it's a story where the girl has some sort of encounter or adventure with Gohan that involves this red machine.