I fairly enjoyed the sides and if its helps yuri had a really pathetic arc in the end after some domestic fluff so id say its worth it just to see Yuri suffer a bit, it also like gives wayyyyy more depth into the teacher's guilt in dating his past student and someone so young (from what i can remember from my last read)
though to be fair i reread a couple times and my first read was the ver w/o nsfw so yuri seemed wayyyyy less of an asshole so maybe that made him more bearable to me in the rereads cause he mellowed out in the end (●'◡'●)ノ

ok i didnt read any side stories but i read the entire main story
this story makes me especially mad because to be honest it didn’t start off so bad, i kept making excuses for the story because yang il woo and i is so good but it just kept getting worse and worse
the ml is such a dislikable character yet the story ends with the mc just dismissing his behavior and them ending up together. the ml had 0 character growth even tho he’s honestly done such weird ahh shit
also the entire plot contradicts itself because it shows how miserable the mc is as a teacher with the kids bullying him calling him a gay pedophile BUT THE THING IS HE LITERALLY IS DATING A PREVIOUS STUDENT OF HIS!! and plus idk if this is true pls fact check me but yuri is a freshman in college!! that kid is fresh out of highschool