Would the miracle in this story be Woojae? Referring to this.. ( It’d really be a miracle to find a character that’s both patient and a great listener in a story. )
The flashbacks are not done. There is one in chapter 46 and is will show some of Hajin’s fault. I agree with you. However, Hangyum did more than kiss her. It was smart but dumb. He was making look like she was jealous and hurt he rejected her and she was lying. He needed to talk to Hajin first but they were not seeing each other and Hajin was avoiding Hangyum before that. Hangyum never knew Hajin’s feelings. Maybe if he did, he would never took that route. Maybe If he talked to Hajin than they would had a better route or maybe agree on that one? I don’t know.. But Hajin seems to be dense and in the past just learning about himself. He has never reveal his feelings and seems to dismiss Hangyum feelings. Maybe he does not understand? It is both.

Hangyum and hajin got issues that they really need to just sit down and work out. Misunderstandings are made when the people assume and don’t even want to listen to their own partner’s explanation. Seriously how hard is it to ask what’s going on? It’d really be a miracle to find a character that’s both patient and a great listener in a story.
They both have done some wrong things like: hangyum kissing a girl (though he was covering up whatever relationship he had with hajin in highschool), he really shouldn’t have taken that route. That leads to hajin being angry (well understood) and badmouthing hangyum, hajin definitely said some too harsh things but he also had a right to be angry after some of hangyum’s actions. And hajin has been lying about seeing jaehee a couple times, which is not good. But at the same time all those times he never cheated on hangyum nor even thought of being together with jaehee again.