It really depends on the specific fanfic. But usually, there would be a group of students who are at the center of the story. Maybe a popular student who is good at sports and academics, and a more introverted student who has some hidden talents.
Another common type of main character could be a student who has a special family background or a unique ability. For instance, a student whose family runs a famous local business in the town where the Hinata High School is located, and this affects how they interact with their peers and the school environment.
The main character could be a Pikachu - Pokemorph. They are usually cute and friendly, and at Lemon High School, they might be the most popular Pokemorph. Another could be a Charizard - Pokemorph, who is strong and a bit of a loner, but becomes friends with the Pikachu - Pokemorph.
Typically, you'll see the main characters from the original High School DxD series like Issei Hyoudou. He might be in a different role in the fanfic, perhaps more involved in the'slave' aspects of the story. Rias Gremory could also be a main character, maybe as a figure of power who has'slaves' under her command.
The main characters are Hinata and Sakura. Hinata with her soft - spoken nature and her hidden strength, and Sakura with her feisty attitude and her growth from a love - struck girl to a powerful medical ninja. In these fanfics, they are often the focus, whether it's their friendship, their rivalries, or their combined adventures in the Naruto universe.
One interesting aspect could be the friendships developed in the Hinata High School setting within the fanfic. Maybe there are characters who start off as rivals but end up becoming great friends through various school events and challenges.
I'm not entirely sure without reading it specifically, but usually in a high school fanfic like this, there would be two main characters. They could be students with different personalities, like one might be really outgoing and the other more shy.
Teachers can also be main characters in some school lemon fanfic. A young and enthusiastic teacher who wants to make a difference in the students' lives could be a central figure. Maybe he or she has to deal with difficult students or a strict school administration. Another type of main character could be the school principal, who has to manage all the chaos and drama that goes on in the school on a daily basis.
The main characters are Akamaru and Hinata. Akamaru is Kiba's ninja dog. His role could be that of a loyal companion and helper. He might use his sharp senses to detect danger or find things for Hinata. Hinata, on the other hand, is a member of the Hyuga clan. She is a skilled ninja with the Byakugan. Her role could be to use her ninja skills in combination with Akamaru's abilities to face various challenges in the story.
Typical characters would include students, like the popular jock, the nerdy student who is really good at academics, and the artsy kid. There are also likely to be teachers who play different roles, either as strict disciplinarians or as mentors. School bullies are also common characters, creating conflict for the main characters.
Sasuke is obviously one of the main characters. He is often the focus due to his popularity from the original source material.
Erza, on the other hand, is a strong - willed and disciplined character. She is often seen as a leader type. In the high school setting of the fanfiction, she would probably be an excellent student and someone who is very involved in school activities.