Maybe a story where the heroes from Boku no Hero Academia are faced with a villain so powerful that they have to seek the help of Saitama. It would be interesting to see how they interact with his nonchalant attitude towards heroics.
One idea could be a crossover where Saitama ends up in the My Hero Academia universe. He might accidentally enroll in U.A. High School. His overpowered abilities would shock everyone, and he could end up being both a mystery and an inspiration to the students. Another plot could be about Deku getting some training from Saitama. Saitama's unique training methods might give Deku a new perspective on how to use his power.
One idea could be a crossover where Saitama from One Punch Man ends up in the My Hero Academia world. He could participate in the hero school entrance exam and completely shock everyone with his overwhelming power. His nonchalant attitude towards heroics might also rub off on the students in a funny way.
One idea could be exploring Tomura's past in more detail. Maybe show his childhood before he became a villain, how he was influenced by All For One. Another could be a story where Tomura tries to redeem himself, which would be a huge twist from his normal villain role.
One idea could be a crossover with 'One Piece'. The heroes from 'boku no hero academia' could end up on the Grand Line and have to deal with pirates while also using their quirks. Another is a crossover with 'Naruto'. Maybe the students of UA could train with the ninja in Konoha, learning new skills and sharing their quirk knowledge. A third could be a crossover with 'Attack on Titan', where the heroes have to face the Titans and figure out how to use their quirks to defeat these huge threats.
In a 'boku no hero academia the gamer fanfiction', the main character could be a transfer student who has a gamer - inspired quirk. They could use this quirk to create strategic plans for hero battles. For instance, they can map out the battlefield in their mind like a game level. They might also be able to recruit other heroes by offering them in - game - like rewards. This would create a whole new dynamic in the relationships between heroes. Additionally, they could use their knowledge of gaming glitches to find weaknesses in villains' defenses.
Another plot could be reincarnating as a student in a different class than the main characters. The protagonist then has to work hard to prove themselves and make their own mark in the hero school, while also interacting with the well - known characters in new and unexpected ways. For example, they might form an alliance with a character who was originally an antagonist in the series.
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.
Well, perhaps a plot where Genos follows Saitama into the My Hero Academia world. Genos could enroll in UA as well and show off his advanced technology - based powers. He might get into a competition with Bakugo over who is more powerful. Meanwhile, Saitama is just casually wandering around, accidentally solving problems and leaving the students and heroes in awe of his effortless strength.
A plot could revolve around Itsuka Kendo forming an unexpected alliance with a villain. Maybe she realizes that the villain has some redeeming qualities or is being forced into their actions. This would put her in a moral dilemma as she tries to figure out how to handle the situation while still being a hero.
One idea could be that Naruto characters are transported to the My Hero Academia world and have to adapt to the different power system. For example, Naruto might be confused by the concept of Quirks at first but then find similarities to chakra. Another could be a training session where Deku and Naruto train together, with Naruto teaching Deku about his never - give - up attitude.