A third idea could be a time - travel harem fanfiction. The main character, perhaps an older version of a well - known character from the future, travels back in time to the present day in the My Hero Academia world. Their future knowledge and different personality traits make them stand out, and characters like Kirishima, Kaminari, and Sero are all drawn to them, creating a harem situation. This would also allow for some interesting plotlines involving changing the future and dealing with the knowledge of what's to come.
Another interesting concept is to set the fanfiction in an alternate universe where the roles are reversed. So, instead of the male characters being the main focus, it could be the female characters who form a harem around a male character. For instance, Ochaco, Tsuyu, and Momo could all be vying for the affection of a male student with a really powerful and mysterious quirk. This would give a fresh take on the harem concept within the My Hero Academia universe.
One idea could be to focus on a new student at UA who has a unique quirk that attracts the attention of multiple characters. For example, a quirk that allows the user to see into people's true emotions. This could lead to some interesting interactions with characters like Deku, Bakugo, and Todoroki. They might all be intrigued by this new student in different ways, and a harem dynamic could develop as they compete for the new student's attention.
Perhaps the OC has a hidden past related to a villain organization, and the harem members are initially suspicious but as they get to know the OC better, they realize there's more to the story. This could create a lot of drama and conflict as the OC tries to prove their loyalty while also dealing with their growing feelings for the harem members.
Perhaps in this genderbend harem fanfic, the female Deku is a new transfer student to a school dominated by male students who are all attracted to her kind - hearted and heroic nature. And they all compete to be her sidekick in battles.
Well, you could focus on the relationships between the characters. Write a fanfiction about a friendship that forms between two characters who initially didn't like each other. For instance, Bakugo and Midoriya could have a different kind of relationship where they become more like brothers through a series of events that force them to rely on each other. Or you could write about the teachers' lives outside of teaching at the academy. What do they do in their free time? What kind of challenges do they face that the students don't know about? You could also write a story where a new villain emerges with a quirk that is completely unexpected and throws the whole hero society into chaos.
A fanfiction focusing on the family lives of the characters can be interesting. Like, how does Bakugo's family interact when he's not around? Or what was Midoriya's father really like? By delving into these aspects, you can add more depth to the existing characters and show a different side of them that the original story might not have fully explored.
How about a fanfiction where the villains and heroes have to team up? There could be a greater threat, like an alien invasion or a powerful quirk - user who is out to destroy the entire world. The heroes and villains realize that they can't defeat this threat alone, so they put aside their differences. This would lead to some really interesting character interactions, like Bakugo having to work with Shigaraki and both of them learning to respect each other's skills despite their opposing natures.
In 'hero academia sludge fanfiction', you might consider a story where the sludge is actually a misunderstood entity. It was once a normal substance but got corrupted by some evil force. A hero could try to purify the sludge instead of just fighting it. They might have to go on a quest to find the source of the corruption and in the process, learn more about the true nature of the sludge.
A cool concept for My Hero Academia fanfiction is to have a time - travel plot. A character could go back in time and change a significant event in the My Hero Academia world. This could lead to a completely different storyline. Or you could write a story centered around a villain redemption arc. For instance, giving a more in - depth look at how a villain like Shigaraki could potentially be redeemed and how the heroes would react to that. Additionally, fanfiction about a tournament between different hero agencies could be really exciting.
A cool fanfiction concept could be to have a character lose their quirk and then have to find a new way to be a hero. This would show their determination and resourcefulness. Or, you could write about a new villain who has a quirk that specifically targets the heroes' weaknesses, and how the heroes would have to work together to overcome this threat.
You could write a 'little hero academia fanfiction' where the heroes have to face a new type of villain that is immune to most quirks. This would force them to rely on their wits and teamwork more than ever. Also, a story about the teachers' early days as heroes and how they trained would be really cool. It could show how they developed their teaching methods based on their own experiences.
Well, he could be an OC with a healing quirk. In the fanfiction, he starts helping out injured students during training sessions. This catches the attention of several female characters. Some might see him as a valuable asset to their future hero teams, while others develop a more personal attraction. The harem could then be formed as these girls start competing for his attention in a friendly way, like trying to bring him the best lunches or inviting him to exclusive study sessions.