Before I get to the critique part, I just want to say that I love this show, I think it's brilliant and the lead actor is truly exceptional! It is one of the best representations I have seen of an Autistic character, but with caveats (below). Probably the best I have actually seen is Asa Butterfield's character in the film "X+Y".
However... as the parent of a gifted Autistic son with similar IQ as the main character, who is at University aged 14, I can say there is quite a lot wrong with the representation of Autism here. This depiction is filled with clichèd stereotypes. It's as though she has taken every trait any individual Autistic person has ever experienced and put them into one person. That's not how it works; it's very much a spectrum, and each individual experiences this neurodivergence differently (and differently at different times). This performance is very exaggerated, particularly in the light of the fact that such high IQ Autistic individuals often hugely compensate with their intellect, and also develop very good masking ability. This is especially true of females on the spectrum; they often present quite differently and are sometimes not diagnosed until significantly later as a result... even more so when they are profoundly gifted like this character. The fact that she is completely 'out' with her Autism (not the diagnosis itself so much, but the physical manifestations) would be highly unusual; there is an expectation that people conform to the 'norm' in society, and I shouldn't think that's so different in South Korea.
That being said, I understand it may not have had the same impact or humour had they made the characterisation more subtle, and whilst the manifestations themselves are largely exaggerated (at least while she's in public), they are truthful aspects of what it is like to be Autistic. The lead actor's delivery and timing is superb, the rest of the cast are excellent, and the show is a complete joy.
