Yes, there are quite a few. You can start by looking on popular fanfiction platforms like Archive of Our Own. There you might find some interesting takes on the relationship between Nezu and All Might. Some stories could explore their different personalities interacting in unique ways, perhaps in a situation where they are working together to solve a problem in the hero world.
Some smaller, more niche fanfiction communities dedicated to the My Hero Academia fandom could also have nezu x all might fanfiction. You might need to do a bit more digging around in these communities, but they can sometimes have some really unique and interesting takes on the pairing that you might not find on the bigger platforms.
A common theme is their shared work environment. Since they both are part of the U.A. High School faculty, many fanfictions explore how they deal with the daily chaos of teaching and protecting the students. Another theme could be their contrasting personalities. Nezu is very intelligent and calm, while Present Mic is more energetic and outgoing. Fanfictions often play with how these different personalities interact and complement each other.
In most cases, it's not appropriate. Fan - created works should be accessible to a wide range of audiences, including younger fans. All Might is a well - known and respected character, and creating explicit content around him in the form of fanfiction goes against the general spirit of the fandom. However, if the 'lemon' is just a misnomer and it's actually a clean story about the relationship between All Might and an OC, then it could be okay.
The relationship in 'izuku x all might fanfiction' is complex and multi - faceted. All Might is not just a mentor but also a symbol of hope for Izuku. Izuku, on the other hand, represents the future of heroism that All Might believes in. Their relationship can also explore themes of legacy and the passing on of a heroic mantle. It often delves into how Izuku copes with the great responsibility that comes with being All Might's successor, and how All Might guides him through the challenges.
A common theme is also the transfer of values. All Might, with his long - held beliefs about heroism, imparts these values to Izuku. This includes things like always helping the weak, never using power for evil, and being a symbol of hope for the people. These values then shape Izuku's journey as a hero - in - training and influence his actions and decisions throughout the fanfiction.
One great 'All Might x Reader' fanfiction is 'A Meeting with All Might' on FanFiction.net. It has a really sweet storyline where the reader character accidentally bumps into All Might in his civilian form and then a friendship gradually develops into something more. It's well - written with great character interactions.
One place to find Nezu x Present Mic fanfiction could be Archive of Our Own (AO3). There are often various fan-written stories exploring different aspects of their relationship, from friendship to more unique interpretations. Just search for 'Nezu x Present Mic' on the site and you'll be presented with a selection of fics to choose from.
A lot of all might x endeavor fanfictions also touch on the idea of redemption. Endeavor has a rather complex backstory with his family issues, and in some stories, All Might plays a role in his journey towards redemption. They also might explore the theme of mentorship, where either one could potentially mentor the other in different aspects, like All Might teaching Endeavor about public relations as a hero, or Endeavor helping All Might with some combat techniques. There's also the theme of friendship that develops over shared experiences, such as fighting against a common enemy or dealing with the politics within the hero community.