A common plot involves Baby Deku showing extraordinary powers at a young age, which causes a stir in the hero society. This can lead to different heroes trying to protect him or villains trying to get their hands on him. Another plotline could be about Baby Deku's origin story being explored more in - depth, like his family situation before he met All Might.
Some fanfictions have a plot where Baby Deku is accidentally sent to an alternate dimension or time. In this new situation, he has to figure out how to get back while also dealing with the differences in the world. There are also plotlines where Baby Deku forms unique friendships with other characters who are also young in the story, and together they go on adventures that are different from the main storyline in the original anime or manga.
Often, there are plotlines where Froppy and Deku are in a sort of mentorship relationship in reverse. Froppy, with her calm and collected nature, helps Deku deal with the stress of being the symbol of hope. They might have heart - to - heart conversations about their insecurities and how to face the challenges of being heroes. And there are also stories where they discover a new combined move using Deku's strength and Froppy's agility and sticking abilities.
One popular plotline is them teaming up to create a new support item. Since Melissa is great at making support gear and Deku is always in need of something to enhance his quirk usage. Another could be a story where they go on a mission together outside of UA, facing villains and relying on each other's skills. Melissa's intelligence and Deku's determination would make for an interesting dynamic.
One interesting plotline could be Deku facing a new, extremely powerful villain that challenges his understanding of heroism. Maybe this villain has a quirk that can nullify all other quirks, forcing Deku to rely on his wits and physical training rather than just his One For All power.
Often, in these fanfictions, there are plotlines where Deku's unique quirk plays a role in attracting the female characters. His selfless and heroic nature, which is enhanced by his quirk, makes him appealing. Some fanfictions might also have a plotline where Deku has to deal with jealousy or competition among the members of his harem, adding drama to the story.
One popular plotline could be Deku and Melissa working together on a new hero gadget. Since Melissa is really into tech and Deku is always looking for ways to improve his hero skills, they might collaborate on something that gives Deku an edge in battles. Another could be them going on a mission together outside of UA. This would test their relationship as they face challenges and rely on each other.
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.
One popular storyline is where Deku and Uraraka go on a special training mission together. They face challenges that test their individual skills and also their relationship as friends. During this mission, they might have to rely on each other more than ever, which deepens their bond.
A third popular type of storyline might be a time - travel or alternate universe one. In this, Deku and Momo could be in a different world where their relationship is more developed from the start. Maybe they are partners in a hero agency right away, and they face challenges that are different from their normal world. This allows for a fresh take on their relationship and different ways to explore their characters.
One popular storyline is where Uraraka and Deku go on a joint mission and during the mission, they have to rely on each other more than ever. Their relationship deepens as they face challenges together and Uraraka realizes new depths to Deku's determination. This often involves them using their quirks in creative ways to protect each other.
There's also the 'Kid Deku in a Different World' trope. In these fanfictions, Deku is transported to an alternate universe, either a completely different version of the My Hero Academia world or even a different fictional universe altogether. This allows for a lot of creativity as he has to adapt to new rules, new villains, and new allies while still being the determined kid Deku we know. It can lead to some really interesting crossovers and unique storylines.