Natsu might use his magic powers to defeat the villains threatening the girl and then offer her protection, thus leading to her becoming his servant.
He could also face challenges within his own guild. Some of the members might tease him, while others might be overly protective. Natsu as a girl would have to navigate through these new social dynamics. Also, his appearance as a girl might attract unwanted attention from some villains who see him as an easier target, but he would prove them wrong with his strength.
Another possibility is that Natsu is turned into a girl by a magic spell gone wrong. As a girl, he discovers new magical abilities or a different way of using his existing fire magic. Maybe the transformation also affects his personality slightly, making him more empathetic and in tune with the feelings of others around him.
Lucy could also play a major role. She might be the one to help Natsu adjust to his new life as a girl. Maybe she gives Natsu tips on how to dress and act like a girl, and they could have deeper conversations about what it means to be a girl in their magical world.
In this 'natsu becomes a girl fanfic', it could center around the idea that Natsu as a girl discovers a whole new side of the magical world. Since he is now a girl, he might be able to access certain areas or knowledge that were previously off - limits. He could also form new relationships with other characters who see him in a different light.
In some fanfics, Harry might have lost his memory or was raised in an environment where information about his parents was deliberately hidden from him.
There were a few novels that could be recommended to readers who liked maidservants and generals. Among them," The Farmer's Door in the Spring " and " A Famous Farmer's Girl Has a Little Field " were ancient farming novels. They told the story of the female protagonist transmigrating to a poor farmer's girl and leading her family to become rich through hard work. In addition, in the ancient romance novel," The Godly Doctor's Daughter: Don't Provoke Me, Your Highness ", the female protagonist transmigrated into the general's daughter. She made plans for the general, fought against the vicious stepmother, and dominated the palace. She could go to the battlefield and fight against villains. In addition," The General's Humble Lady " told the story of a woman who was forced to marry a general, but was attracted by the general's loyal servant girl. These novels all had elements such as transmigration, house fights, farming, and so on. They were suitable for readers who liked these kinds of topics.
It could be an evil wizard. There are many powerful and malevolent wizards in the Fairy Tail universe who might target Natsu for some reason and use dark magic to make him cold.
Natsu might be a powerful wizard with a big heart. The little demon girl could be an outcast among her kind, which is why she's alone in the forest. There could also be other side characters like Natsu's friends who might later get involved in the story when he tells them about the little demon girl.
There could be a female dragon named Ignis who is very fiery and passionate, always trying to be the closest to Natsu. Another could be a more gentle dragon named Aqua, who has water - based powers and uses her calm nature to balance out the more intense dragons in the harem.
In addition to Lucy and Erza, there could be other female characters from the series. Maybe some minor characters who have always admired Natsu from afar. For example, that one girl from the guild who always blushes when Natsu is around. Another possibility is a powerful female dragon who sees Natsu's transformation into a Dragon God as a sign of his worthiness. She might join his harem, bringing a different kind of relationship dynamic as she has her own dragon - like qualities and power. And there could be a female mage from a different guild who hears about Natsu's new status and is intrigued, eventually becoming part of his harem.