I hate Mincheol as a person, but I loooove his character. Taehee too. Taeha and Haesoo just... feel like every other Fl and ML, but I love seeing real depth in these types of characters. Characters that, even if it's not good or one we understand, have a reason for being the way they are instead of just the "evil bastard who exists to make the male lead look a little less evil". I can only hope we start seeing more depth in Lee Jay too. I could write essays on those three.
I'm invested in them more then the main couple of this.

Atp the only character that seems to have a speckle of depth is Mincheol, as much as I dislike that motherfucker. Author did a good job at potraying his narcissism, as for the rest of the story itʻs a lost cause bc of the progression, imo.
(before anyone hates on me, no Iʻm not a mincheol fan nor do I support him )