I don't know why many people hate hyesung I mean if he really abandoned byul when he ran away he can just go to another country but he stay with heesoo and ask about byul. Even he blame himself when he can't take care of byul really well ╥﹏╥. His character development really good phase but you can't blame him when he lock himself when he meets that bastard. He also say sorry to byul because he don't want byul see him in that state. He want byul have happy family and saw his parents strong and have good relationship. Even I hate dojin in early chapter but I respect him when he know his partner want some space to overcome his trauma.
I like the story because the age gap similar with my parents so I get heart warming felling.