Responses
Because Sunyool is more like a brat than a jerk and he's not manipulative like Heejae. Also I think his straight forward personality to show his love to Jisuh is admirable for readers. But I can't agree more with what you said, Heejae is somewhat feel more relatable to me too (๑•ㅂ•)و✧ just I hope he will not fall to the dark side again. His character development is admirable in this point.
I kinda really liked Heejae tbh. Even right from the beginning, just because I feel somewhat relateable on his anxiety like the confession thingy. It's amazing on how much he can change all because of Jisuh. He may be a jerk before, but he is slowly trying to change.
I mean, Sunyool was also a part of the plan with Heejae before. I don't see how you guys never complain about him lol. But he is a cinammon roll. I dont hate him, he's cute lol