One possible reason could be that she's different. In many fictional worlds, being unique can make a character a target. Maybe her appearance or her abilities set her apart in a way that makes others jealous or feel threatened.
Teaching the bullied kid self - defense skills, not in a violent way but more about how to be assertive. They can firmly say 'no' to the bully. Also, encourage the kid to make more friends. Bullies are less likely to target a kid who has a strong group of friends around them.
The 'akaza sad story' might refer to the tragic backstory of Akaza from Demon Slayer. Akaza was once a human with a strong will. He had a family and a normal life, but due to various misfortunes and being turned into a demon against his will, he lost his humanity and was forced to do cruel things. He also had a lot of inner struggles as he still retained some of his human emotions deep down, which made his story a sad one.
The girl could find allies. Other kids who are against bullying can form a group with her. They can support each other and work together to raise awareness about bullying in their school or community. This way, not only can they protect the girl from further bullying but also prevent others from being bullied.
Some fanfictions may have the theme of resilience. Romano could show great strength in the face of bullying, not letting it break him completely. There might also be a theme of finding one's voice. He could start off being unable to stand up for himself but gradually learn to speak out against the bullies. And the theme of change is possible too. The bullying experience could cause Romano to change his behavior or attitude either for the better or the worse.
One common theme could be Natsu's struggle to overcome the bullying. He might initially feel alone and defeated. Another theme could be the discovery of true friends who stand up for him. For example, his Fairy Tail comrades could find out about the bullying and rally around him, showing the importance of friendship in difficult times.
Often, the setting plays a role. If it's a school setting, there could be elements like teachers not noticing or not doing enough about the bullying. This can create a sense of injustice. And then there's the theme of change. Maya might work towards changing the situation, either by getting the bully to change or by changing the school's attitude towards bullying.