Harry Potter could also be a significant character. He is close friends with both Hermione and Ginny. He might witness Hermione telling off Ginny and try to understand the reasons behind it. His perspective could add more depth to the story as he might have his own thoughts on who is right or wrong.
Ron could be one of the main characters. Since he is Hermione's boyfriend and Ginny's brother, he might be caught in the middle of their conflict. He could try to play the peacemaker or end up taking sides, which would further complicate the situation.
Luna Lovegood could be involved. She has her own unique view of the world and might offer some unexpected insights during the conflict between Hermione and Ginny. Maybe she tries to diffuse the tension in her own dreamy, yet wise, way.
In this fanfiction, it could be that Ginny is involved in some sort of gossip or spreading rumors. Hermione, who values truth and integrity, confronts Ginny about it. She might scold Ginny for being irresponsible with her words and how it can harm others' reputations at Hogwarts.
In many fanfictions where Hermione confronts Ginny Weasley, it often stems from a conflict over a boy, like Harry. Hermione might feel that Ginny is being too forward or not taking Harry's feelings into account. For example, if Ginny is making big moves on Harry without considering how it affects his studies or his mental state, Hermione, being the practical and studious one, could confront her. It could also be about their different personalities clashing in the context of the wizarding world's social dynamics.
It could also be related to a boy. If both Ginny and Hermione are interested in the same guy, say Harry Potter, Hermione might stand up to Ginny to assert her own feelings or to clarify some misunderstandings that Ginny has about her relationship with the boy. This can create a tense situation between them in the fanfiction.
In Ginny and Hermione fanfiction, Ginny is often portrayed as bold and adventurous. She's not afraid to take risks and is very confident in her magical abilities. Hermione, on the other hand, is the brains of the duo. She's highly intelligent, studious, and always has a plan. Their combined characteristics make for an interesting dynamic. For example, in many fics, Ginny's impulsiveness might get them into a tricky situation which Hermione then uses her wits to get them out of.
Scorpius Malfoy (again, in a fictional author sense) could write some interesting Ginny and Hermione fanfictions. He might bring in his family's perspective and create stories where Ginny and Hermione have to interact with the Malfoy family in some way, perhaps to heal old wounds or to work together on a project for the betterment of the wizarding community.
I'm not sure specifically if there is a fanfiction with exactly that premise. But given the vast world of fanfiction, it's very possible. It could be an interesting take on the characters, but also a rather strange one considering Ginny and Hermione are friends in the original story. Maybe in this fanfiction, the author has a unique backstory or reason for Ginny to be 'out to get' Hermione, like a misunderstanding or some new plot device.
They are popular because they are both strong female characters. Ginny is brave and talented in Quidditch, while Hermione is extremely intelligent. Their different strengths make for interesting combinations in fanfiction stories.
I really like the fanfic 'Magic and Unity'. In this story, Hermione and Ginny team up to create a new spell. It shows their intelligence and creativity. Their interactions are so well - written, and it also includes other beloved characters from the Harry Potter universe, which makes the whole story very rich and enjoyable.
Obviously, Harry would be an important character even though he leaves. His actions before leaving and potential return would greatly affect the story. Also, the Weasley family, especially Ginny's mother Molly. Molly would probably be very involved, offering her motherly advice and support. Ron and Hermione might also be involved. Ron as Ginny's brother would surely have an opinion and Hermione could be there for Ginny as a friend.
Another storyline might involve Ginny and Hermione teaming up to solve a mystery within Hogwarts. Maybe there are strange disappearances of students and they use their combined skills, Ginny's Quidditch - related quick thinking and Hermione's vast knowledge, to get to the bottom of it. They might suspect a hidden chamber or a rogue spellcaster. They start by interviewing students and staff, gathering clues from different parts of the castle, and finally unmask the culprit.