The School series (especially 2013 & 2015) revolve around school violence, grade, suicide & so many other issues that young Koreans face everyday especially in high school. I like these series that try to tackle real society issues that still are a big flaw in modern SK society with one of highest suicide rate in the world amongst the young.
Kim So Hyun did an amazing job playing the 2 main characters! It is my favorite School sequel. If you prefer ont hat is more lighthearted, I’d suggest you to watch School 2017.