i know for a fact that illumination does not own hotel Transylvania and it would not make a whole lot of sense for them to be in the same world legality wise but i am going to ignore this in favor of Worldbuilding and the convoluted happenstance that would allow the minions to reveal this specific part about their biology
i was in the shower thinking about how most tv show adaptations of "popular character's daughter/son/child goes to high school and meets other high school kids of other characters" end up sucking absolute ass unless it's monster high and/or ever after high (and even then, the bar raised by them can be dunked on in the sense that they don't do enough representation). so i went "what if i made my own for a movie that hasn't had this happen to it yet"
so Transylvania High; a school for both monsters and humans alike. this school was originally a private school that was kept hush-hush due to past stigma concerning monsters, but now that recent years have proven that this stigma has been going way down, they decide to open up publicly. Transylvania High takes place in, well, Transylvania, not to far from the titular Hotel Transylvania. Go figure.
i am starting off strong by making the main character, Denise, a trans fem future version of Dennis (who was introduced in Hotel Transylvania 2 and has returned in the later iterations of the franchise, albiet not at the same level of relevancy). this isn't explicitly mentioned in the first two seasons of the show. Denise also has a younger brother, Mavlo, who is similarly trans masc, and notably human despite taking on a lot of Mavis' features. Denise and Mavlo attend Transylvania High alongside Winnie (and the rest of the wolf pups), and probably creatively named kids of the other characters.
"wheres the minions" IM GETTING TO IT!
i'd also imagine that the kids from other franchises made by illumination/sony/whatever (sans boss baby and trolls on account of i hate them and i can't find a way to shoehorn them in, same with anything else i don't mention here). yes this means gru's daughters are attending high school here.
how they get here tho? - so Margo is going to college now, located in Transylvania, and given that Gru is Overprotectives Georg but also respective of Margo's wishes, he researches the town nearby and finds out about Transylvania High. 1+1=2, you get it. He isn't outright about moving there to make sure Margo is safe and instead says that he saw Transylvania High is an extremely reputable school for Edith and Agnes. Margo is suspicious of him but buys it. This is plot relevant.
"the truth come out: how the minions do gay?" I AM GETTING TO ITTTTT!!!!!!
there'd be some overarching plotline in the first season about Denise trying to get her brother excited to meet new people for once, now that they can go to school together, Edith and Agnes excited to go to a school with monsters, maybe even a magic learning class whatever. the ending plotline for season 1 would allude to the school's history, revealing that there's more to the school (both building, lore, and teacher-wise) than initially thought. maybe one of the kids, idk Edith ends up accidentally releasing an ancient curse and they have to stop it for the finale. idkkkk
season 2 is where we get into the thick of it. the school gets a new monster-human advocacy system instated by The Government or whatever. unfortunately, the human advocates and the monster advocates still fucking hate each other and are not willing to back down on these grudges. i have no ideas for names or designs but i do know that they're both paid by two different political leaders and may or may not be spying on the adults who are teaching there as well as the Secret Magical Artifacts that The Kids recently discovered exist in a Secret part of the school. i'd imagine the human side comes from one of the many villians/antagonists that gru has dealt with in the past or alluded to in the past that then followed him here. the monster side would definitely also either come from Transylvania to keep things halvsies halvsies. maybe like a wolfman or smthn idk.
anyways Edith proves to be really surprisingly good at magic but usually uses it for troublemaking purposes. being a nusiance to school teachers, causing fights, damage, all that. Agnes also proves to be good at magic but is trying so so so hard to not use it for the purposes her sister is. maybe we get to see Margo more in this season because reasonably she'd visit and maybe pick up/drop off her sisters during school activities. i'd like to imagine some of the minions enroll as a student but it's just 3 of them in a trench coat, mainly bc gru 1 wants to keep an eye on the girls 2 doesn't trust the new human advocate once he finds out that they exist.
Denise forms some kind of bond with Agnes during this season about how sometimes it sucks to be associated with a sibling that is known as weird or a jerk by the student body. Edith eventually finds out that people are mistreating her sister due to her actions and starts to get extremely bitter about it. Mavlo opens up about how often he felt guilty about being the weird younger brother of Denise.
meanwhile the minions like. slowly find out the human advocates are part of some political takeover of Transylvania and they do not like the monster population of Transylvania at all. Gru says no to speciesism. the human advocates try to recruit him and this goes extremely poorly. a building gets blown up probably idk. the kids end up thinking it's the monster advocates causing the issue because Denise and Mavlo immediately assumes it's someone from that side due to how Dracula used to be about humans. eventually the monster advocate is actually just unfamiliar with them and warms up to humans, and plans to doublecross the political side he was working with. he probably does this as he has to be a part time security guard making sure that Edith stays on good behavior.
season 2 has a finale where the human steals one of the artifacts from the lower layer of the school and plans to take over not only Transylvania but the world on account the artifact also corrupts their mind once they come in contact with it. the only solution is the kids finding someway to break the artifact and then the real police get involved. the political tensions are temporarily dispeled, however the monster advocate goes missing!!!
"when d-" i- OK FINE! DAMNING CHRIST
season 3 is when the girls eventually meet the Dracula family at the hotel and that's also when they ask about Denise being on HRT. they then mention this to Gru who didn't know it was legal for them at this age to do that. there's a weird moment where this is mistaken for Gru being transphobic but after a series of really convoluted events it's revealed that not only the minions are asexual creatures that cannot be gendered by human gender terms, but Gru and Lucy are a T4T couple.
Edith finds out they're agender after all of this and starts dressing even more masculinely than before. There is still strain on the relationship between them and Agnes though that's for the reasons stated in s2. Edith doesn't explicitly come out about this yet though and still has no idea what name they'd go by, they just say 'hey my pronouns are they/them now' and everyone goes 'ok cool!'.
Edith makes a demon bond pact whatever after finding some demon that had been trapped under the school. this is because they are impulsive and they still don't like the fact people are being mean to their sister, and are also starting to think their sister hates them. this goes as well as you would expect. the demon kind of got trapped there back when the school was still private due to bullies trapping him in whatever thing Edith fucks around with.
subplot b includes Margo trying to figure out why the monster advocate went missing after the finale of s2, seeing as he did not appear at any time during that debacle and that's kind of concerning. what's even more concerning is that she keeps getting cryptic messages through crows.
subplot c is like. idk. minions causing issues as a student spy. maybe gru has Dr. nefario make a robot student spy and this goes horribly horribly awry, proving that maybe the minions are better at being spies in this situation than a machine. whatever
this is all i have for rn. its like 5 in the morning and i did this all by riffing and memory. like i am improvising all of this here. this is me spitballing. throwing spaghetti at the wall as a certain strider would say
i am also electing to ignore the hotel transylvania miniseries as that's about MAVIS and events PRECEDING hotel transylvania. i am expanding upon her kid. however i do kinda like the artstyle it has going on so i may rework the artstyle a little bit and go from there when i draw Denise and Mavlo.
Mavlo is a character i made up btw. he's non canon. he's also extremely goth/emo/punk/etc. and is incredibly introverted, but as the series goes on he becomes more comfortable with people and better able to vocalize his boundaries about it.