One common emotional moment is when Izuku is physically injured during a battle. In some fanfictions, he might be seriously hurt while protecting his friends. This shows his selfless nature and makes readers feel for his pain.
One great 'Boku no Hero Academia Izuku' fanfic could be one where Izuku discovers a new, hidden quirk within himself that's not related to One For All. This could lead to him having to train in a completely different way and form new relationships with his classmates as they all try to figure out this new aspect of his powers.
Bakugo is often paired with Izuku. Their complex relationship can add a lot of drama to the detective story. Bakugo might be reluctantly helping Izuku or even be a suspect in the case Izuku is investigating.
One common theme is empowerment. Since female Izuku is often in a male - dominated world of heroes, these fanfictions usually show her rising above the challenges and proving herself. For example, she might have to face discrimination from some of the male characters at first but then shows them what she's made of.
Obviously, Izuku Midoriya is the central character. Then there are often characters like Ochaco Uraraka, who could be part of the harem as she has shown an interest in Izuku in the original series. Tsuyu Asui might also be included as she is a close friend and could potentially develop deeper feelings for Izuku in fanfiction.
Often, a common element is a distorted view of Izuku's power. Maybe his One For All power goes out of control in a terrifying way. Another element could be that the normally friendly characters in the Boku no Hero Academia world turn against Izuku, creating a very scary and isolating situation for him.
A major theme is also the idea of support. The characters in the harem are often there to support Izuku in his journey to become a great hero. This can include emotional support, like when he's feeling down about his progress, or practical support during battles or training. And of course, there's the theme of love and attraction, which is a fundamental part of any harem story. Different characters in the harem will show their love for Izuku in various ways, whether it's through acts of kindness, protecting him, or just being there for him.
Emotionally, when Izuku is hurt, he becomes more empathetic. He understands the pain of others better. In some fanfictions, this is shown by his interactions with his classmates who have also faced difficulties. He can offer support based on his own experiences of being hurt.
The unique quirk concept. Izuku with a light quirk offers a fresh take on his character. It allows for different power - based storylines compared to his original quirk in the canon.