Neurodivergence in High School Frenemy
Okay so Chadjen is on the spectrum, but as I kept watching the show and revisiting a lot of scenes, I realised so are Saint and Shin. I'll have to rewatch School 2013 since the first time round, I wasn't aware about neurodivergence or that I was audhd myself, but Go Nam Soon/Park Heung Soon definitely are on the spectrum as well.
Back to saintshin, Shin is high masking and he's either got autism or audhd. He displays a lot of positive traits of them: empathetic and justice sensitivity (see how he reacts to his classmates getting bullied and how protective he is) and self-awareness (the way he acts around Saint makes it very clear that he knows he's in love); but also negative behaviours like being self-destructive. It also adds to his connection with Chandjen. Whether you know you're neurodivergent or not, unconciously you tend to find each other and form bonds with other nds (which further explains saintshin becoming such close friends apart from being giants lol).
As for Saint, he's definitely a raging case of untreated adhd (could also be audhd). Not all boys get aggressive mind you since neurodivergence IS a spectrum and not everyone is the same, but Saint did in the past. The catalyst to his change was hurting Shin. Knowing that your out of control anger destroys everything... Saint reminding me of myself (IM NOT OKAY). Not to mention his lack of attention in class, an inability to concentrate being seen as 'lazy'. Probably gets his neurodivergence from his dad or mom or both. The fact that his dad is also an alcoholic - people with adhd have high chances of addiction/substance use (is Saint 'addicted' to Shin and vice versa lol).
Same with Shin who probably gets his austism/audhd from his mom - also meaning that Chingching definitely has it too and why she's so attached to Saint.
Final verdict:
Shin - Autistic or Audhd (leaning more towards Audhd), Saint - Adhd or Audhd (leaning more towards adhd), Chingching - Adhd or Audhd (not enough data to confirm, but shes definitely nd).