A normal person's range of emotions watching this show is a mix of shock and cringe at the start, cringe at the middle, and sadness at the end. Nagatoro abuses, manipulates, embarrasses and traps this poor upperclassmen into a skewed relationship, and the cuck author spends the last few episodes trying to convince you that they're in love. It's called Stockholm syndrome and if you buy into this 'love' you either have some massively warped interpretation of love at the disney level, or you're a horny beast who likes to stepped on, my brother.
Looking at this through a scholarly lens it's actually quite impressive, to so expertly bully someone then by acting coy and shy occasionally make them think they're in love with you is a feat worthy of praise. This author tries to use these coy and shy moments to illustrate a frail maidens heart, who can't express herself to a boy she admires, but ends up a blueprint for a serial manipulator instead. You're telling me she finds a lonely, excluded upperclassman who spends long hours after school alone in a club room drawing and decides she likes him??? No to most women he is a loser and I'm guessing she thought the same. She finds out this lonely man likes to draw fantasy manga, decides to relentlessly bully him and make him cry day after day because she finds it interesting, then the author in his meth induced confusion decides to portray them in love.
There is no progression that can explain these changes except the author and a needle containing meth. The upperclassman stays the same throughout the story, only coming out of his shell a little bit while finding comfort in these newfound friends who are actually bullies. There is no formula which explains how Nagatoro would fall in love with him unless she just enjoys the bullying that much, which she does. She even tries to act jealous when others get close to the upperclassmen which is exactly how a manipulator would act, especially with the class president, I just feel bad for the guy the whole time. I started and finished this show sad and horny.
It might odd to scrutinize a fanservice show so heavily, but I think the author's writing is just too poorly thought out to ignore, and he even tries to change lanes to a love story at the end, it's fair game. It is genuinely damaging to try to portray this as a love story as it is so warped both in lead up and execution. It sums up two things I hate; poor story and tsunderes.
If you still want to enjoy this show, I recommend secluding yourself in a cave and edging yourself for several years and then you will be fully equipped to deal with this mess. The art in Nagatoro is pretty good also.
