Ochaco Uraraka is a common character in the harem. Her kind and friendly nature makes her a likely candidate. Momo Yaoyorozu is also often included. Her intelligence and elegance add an interesting dynamic to the harem. And Tsuyu Asui could be part of it too, with her unique personality.
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.
Well, it could be really interesting. Gohan, with his Saiyan powers, would be quite a unique addition to the My Hero Academia world. In a harem situation, he might attract various female characters from MHA. Maybe his strong sense of justice and his power would make him a popular figure among them. He could potentially form relationships with characters like Ochaco, who has a kind heart and might be drawn to Gohan's good nature.
One common storyline is Deku having to balance his relationships with different female characters while also dealing with his hero training. For example, he might have to choose between going on a date with Ochaco and attending a special training session with Tsuyu. Another storyline could involve the girls in the harem teaming up to support Deku during a difficult battle, like when he faces a powerful villain. Sometimes, there are also stories where Deku initially doesn't realize he has a harem and the girls are all secretly vying for his attention in their own unique ways.
In some My Hero Academia lemon harem fanfiction, a plotline might be centered around a character who is an outcast in society due to their quirk but is actually really powerful. They end up at UA and the female characters see the good in them. The girls might start to help the character control their quirk better, and during this process, feelings develop. Another type of plot could be that there's a character who can travel between different dimensions, and in one of these dimensions, they meet the female characters in a different context, like a post - apocalyptic world where they have to rely on each other to survive. This creates a bond that turns into a harem - like relationship.
In My Hero Academia Izuku Harem Fanfiction, the 'accidental closeness' trope is quite prevalent. For example, Izuku might accidentally fall on one of the girls in the harem, leading to an embarrassing yet cute moment. There's also the 'rivalry - turned - love' trope. Some of the characters who initially see Izuku as a rival might later develop feelings for him and join the harem.
Gohan could fit in by being a transfer student. His Saiyan powers would be seen as a very unique 'quirk'. In the harem aspect, his kind heart would draw the attention of the female characters. For example, Mina would find his positive attitude infectious.
One way to create engaging characters in a My Hero Academia harem fanfiction is to give them flaws. No one is perfect, and this is especially important in a harem situation where there are multiple characters competing for attention. A character might be overly jealous, which causes problems in the harem. Another character could be too self - centered and have to learn to be more considerate of others' feelings. Also, you can introduce new aspects of their quirks. For example, a character with a super - speed quirk might also have a side effect that they have to deal with, like getting dizzy easily. This makes the character more interesting and relatable, and it also adds to the drama and intrigue in the harem.
Definitely Ochaco Uraraka. She has feelings for Deku in the canon story, so she's a natural fit. Then there's Jiro. Her music - based quirk and her cool attitude can be really appealing in a harem setting. Toru Hagakure, the invisible girl, also shows up a lot. Her unique quirk and her kind heart make her an interesting addition to the harem. And Nejire Hado from U.A.'s Big Three also sometimes appears in Deku harem fanfictions, adding a bit of an upperclassman allure.
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.