Here are pictures of our favourite monster gym teacher! Adult wise, I think Karasuma is my favourite; I just like his stoic and professional personality as oppose to Koro-sensei’s funny personality and Bitch-sensei’s... um.. lewd personality. I honestly think he does care for these students in his own way; but he’s so stoic and so professional, that he draws the line between that and his own feelings. 

That’s the thing with Karasuma, he doesn’t express his feelings at all. There’s question to why that is, perhaps he does have some kind of mental deficiency where expressing emotion is difficult for him and that is why he opts for a professional attitude. Plus, there were many posts depicting Karasuma as asexual and aromantic as throughout the manga and anime, he is unaffected by Irina’s advances and got visibly disturbed when Irina mentioned something about “making love” (having sex) about 10 times a day (which in all fairness, is a ridiculous amount of love making). 

And of course... his monster quality comes out when he smiles or fights or exists. Notice how the only times he smiles is when he’s strangling someone (last panel on the right) and scaring the living shit out of a bunch of dogs. It is a terrifying smile that could probably make children cry - this also might be the other reason why he doesn’t show emotion. 

The middle one is just him being an adult. XD. It’s like Dad is getting scolded by Mom because Dad dragged all of their children into something dangerous/stupid and now Mom has to fix everything. (Lol, mother and father relationship between Karasuma and Koro-sensei; just like Tamaki and Kyoya from OHSHC)