I honestly wished for sensei to turn out to be a sadist or a very violent guy for a moment

i feel you! I was like "go mad shit crazy or have some yakuza connections" xD i think Harada spoiled me a bit and now i keep thinking of twisted stuff. or it also reminded me of ogeretsu tanaka's work where the "M" type actually is a BIG "S".
anyway poor sensei. that just sucks