To quote someone smarter than me: "Huh?"

I feel like Rui's autism is baked into his character to a point I can't even conceptualize a reading of him where that's not taken as a baseline.

In the shortest way I can put it: Just read any Rui content in the game, with main story and his events being most explicit about it, but they constantly drop bits and pieces related to how his autism has defined so much about his life, including the way people misunderstand him and his problems with identifying his feelings, etc.

For a longer response, childhood flashbacks we see in his second event are all about this.

Rui trying to connect with his classmates/kids his age: showing them a moth he's holding bare handed while infodumping about cool moth facts he knows that other kids get scared of. His interest in robots being due to having problems socializing with other kids in a way they see eye to eye with him, so he was actually trying to make himself a friend so he won't feel lonely during summer breaks.

The way he starts to talk about said robot idea while his teacher has been praising him for winning a robotics tournament with a robot leg he made, starting to infodump yet again only to stop when he realizes others are dismissing it as Rui being a genius and "something they can't understand" and that it is more about their sense of envy towards him for that, in their eyes.

Rui hyperfocusing on things, being hyperverbal, having problem recognizing when he makes a social faux-pas/that other side isn't interested in what he has to say about his hyperfixations/special interests are all things that repeatedly come up throughout both RMD where above examples comes from, and in any content he has in the game.

In fact, even with Nene initially part of their problem connecting was that Rui going motor mouth intimidating her, especially since she was already struggling to talk to others, and clearly struggled with speech and words at the time, and it was part of why it was after the Little Mermaid show they really managed to click.

Not to mention, another big point from said event was Rui himself asking his mom if he is different from other kids, and her immediately guessing something must have happened at school, which kid Rui confirms with saying that all his classmates and teachers say that he's different from rest of his friends.

And that's where his mom drops that yeah, he might be a little different from other kids around him, but being different isn't a bad thing. How she used to have people call her eccentric and a weirdo for devoting herself to biology research since she was little. And how she met Rui's father, who's similarly as devoted robotics and finally thought to herself she finally found a friend.

Entire conversation is about how Rui's parents are at bare minimum neurodivergent themselves, and realistically autistic, given main point they connected over was their own respective devotion to their special interests being that strong. And her urging Rui to not be ashamed of his own interests with saying as long as he holds them dear to his heart, he would someday make friends like how his parents met.

Said parallel itself already feels like autistic mom to autistic son talk to begin with, but if saying some additional things from other events/other relevant things to above as well-

Rui's hate of vegetables is actually about his sensitivity to texture and taste of them, which is a common autistic trait. He's been confirmed to hate watermelons in a Q&A, as he can't stand texture of any of the melon family.

His show outfit made by Mizuki was noted to be really comfortable to move in, and he generally seems to prefer looser and comfortable looking clothing. Sensory issues with clothes are also common in autistics.

He has multiple events dedicated to his problems with recognizing and understanding his own emotions, with his first event being most blatant about it. He'll act in reaction to things but he won't recognize those reactions must have came from what he feels, and even in later events where he starts to get better at recognizing at least there is something troubling him emotionally, he still needs help from loids and others in the cast to figure out /what/ he's exactly feeling. Alexithymia is also extremely common for autistics.

Generally a lot of what is read about him as dangerous tends to be very common autistic guy being assumed to be creepy/school shooter/lacking empathy, latter of which especially being a thorn on Rui's side, given a big part of the reason why he stopped trying to connect with others early game was because he was concerned about troubling others.

In RMD, when his classmates reads him jumping out of the window to show he took all the necessary safety cautions, he can't understand why other kids got scared of what he just did (trouble reading social cues/social norms- autism symptom), and his takeaway from other kids calling him scary, creepy and abnormal was that he troubled them by pushing his shows on them; 'double empathy problem' with allistic people assuming autistic person is not capable of empathizing with them due to flat affect/the way he shows his empathy being by trying to help them with the problem than give socially appropiate emotional reactions are all relevant in Rui's case.

His special interests also comes up with area conversations on how he has a fascination with platypus, to the point he's checking a kids' exhibit on them, and when prodded by Emunene he immediately starts to infodump about it, where Emu says he could be a great biology teacher and Nene says she said the same to him multiple times, but he always insists it's just a personal interest to him.

And naturally, directing itself being a special interest to him, with him canonically having watched plays of his director idol, Tom Gray, hundreds of times, and this has been a connection point with him for Asahi in his third event, where entire conversation is really two autistics with same special interest talking about it.

His hyperfocus also comes up in the amount of times he ends up spending entire day or night working on some props/something show idea related, coming up as early as in his first event's side stories, where Nene mentions it's not rare for him to not notice time or even forgetting to eat when he gets caught up in something.

And in general that tying to how and why he'd end up missing the social cues when he gets an idea, and end up driving people away accidentally, as Nene herself helpfully spells out in main story.

Rui himself mentions it to Toya in Ode event, that he's been told multiple times that he's someone who stops at nothing if it's for the sake of achieving a goal (aka that he's ruthless), but in truth he just would get so caught up in the show idea he just came up with that he would end up losing sight of others. And how that leading to not not having any sense of moderation would ultimately end up in others leaving.

All of which, again, are signs of autism, especially when you put together all of the above (and I'm sure more I'm forgetting here, as this is all off the top of my head).

I hope you find this helpful, anon.