Well, emotionally, these look like normal students to me. I went to university many ions ago and life was pretty much sex, alcohol, lectures in that order. For a few with disordered behaviour it would take another ten years or so before they would be reliable enough to mate for life and have babies. Humans in their late teens are not grown sufficiently to produce the unselfish behaviour that is needed for romantic attachments whilst studying. For me, the webtoon and scriptwriters have judged this well. The cast are not toxic, they are simply acting.
Don't forget that the Covid pandemic was raging at this time and all the cast and team should be applauded for getting through a difficult production. Well done.