Perhaps Natsu is seen as a bad boy because he's from a different background than most of the students at Fairy Tail School. He might come from a poorer part of town and has a rougher attitude. He could be constantly getting into fights with the rich kids who look down on him, and through these conflicts, he learns about friendship and acceptance.
Maybe Natsu is seen as a bad boy because he challenges the traditional rules of the academy. He might believe that some of the rules are holding students back from truly exploring their magic potential. So he forms a sort of rebel group within the school, and they go on adventures outside the permitted areas to discover new types of magic. This could create a lot of conflict with the school authorities.
He could be a bad boy because he's always skipping classes to go on his own little adventures around the academy grounds. He might be more interested in exploring hidden parts of the school or finding new magic spells on his own rather than sitting in a classroom. This would make the teachers view him as a disobedient student.
He would probably have a very rebellious look. Maybe he'd wear his scarf in a more unkempt way, his hair a bit messier. He'd be the kind of guy who walks into class late without a care, smirking at the teacher. His attitude would be nonchalant towards the school rules, always ready to break them if it means having some fun or standing up for what he believes in.
In 'natsu the fairy tail highschool bad boy fanfiction', it may center around Natsu's character transformation in a high school environment. Since he's a bad boy, he might start off as a bit of a rebel, not following the school rules. But as the story progresses, he could meet someone special, like a new friend or a love interest. This encounter might change his perspective and lead him to become a better person, while still maintaining his unique charm and the magic - filled world of Fairy Tail.
Obviously, Natsu would be one of the main characters since the title mentions him. There might also be other Fairy Tail characters like Lucy, who could be his friend or love interest in the high school setting.
One idea could be a story where Natsu and Juvia team up for a mission. They initially clash because of their different personalities, Natsu being hot - headed and Juvia being more reserved and love - stricken for Gray. But as the mission progresses, they start to understand and respect each other's strengths, and form a strong friendship. For example, Natsu could learn about Juvia's water magic and how she can use it in creative ways, and Juvia could be impressed by Natsu's determination and never - give - up attitude.
Perhaps as the Fourth Master, Natsu discovers some long - lost secrets about Fairy Tail. These secrets could be related to the origin of the guild or some powerful magic that was hidden away. He then has to figure out how to use this knowledge to the guild's advantage without causing chaos.
Another possibility is that the kid is from an alternate dimension where time passes differently. Natsu's kid shows up in the Fairy Tail world and he has to figure out how to be a father. The story could focus on their journey to get to know each other and the kid's adjustment to this new world.
One possible reason could be a past trauma. Maybe he witnessed something really horrible during a battle or an incident at school that shocked him so much he lost his ability to speak. For example, if he saw a friend in great danger and was powerless to help immediately, it could have had such a psychological impact on him.
Gray Fullbuster can often be portrayed as a bad boy in fanfiction. His cool and sometimes aloof attitude, along with his stripping habit which can be seen as a bit of a rebel trait, makes him a popular choice. Another one could be Gajeel Redfox. He was originally an enemy but joined Fairy Tail. His rough past and tough exterior give him that bad boy vibe.