As someone who is currently in highschool, the best part was (and mostly in every KBS school 20-- drama) was the fact that the characters and their life was relatable. The main characters didn't include a chaebol or something extra. They were all just normal students with their own personal problems like parents not supporting their dreams, losing loved ones, favoritism and corruption in schools, your crush not liking you back etc.
I won't say anyone except Yihyun a good job at acting but they all are rookie actors, and this drama also didn't require a lot of expressions and all, hope their skills improve in the coming projects.
if I rank all the KBS school dramas, then the rankings will be: 15; 21=17; 13
Ig u should watch it if you liked school 2017
also, it's more of a binge watch drama i must say cuz there are not much intriguing hooks.