Comment by CeaserDickSupremacy on Nate

No he didn't. Hosik was Hyung's servant(in their past lives). They grew up together but ended up in a relationship. Hyung was then made to marry a woman so that he can have a child(the little boy holding on to that lady who is his mom and Hyung's wife). Hosik then got sick but brushed it off and then Hyung left for some business(on Hosik's  insistence) even though he had a bad feeling about leaving Hosik behind, when he came back Hosik was already too sick and there was nothing they could do so he died.

That's why you see Hyung being overly protective and anxious, he can't help it since he and Hosik are reincarnations of the Hyung and Hosik of the past, he can't remember the past but the feelings of loss and pain linger in him and everytime he is away from Hosik he keeps feeling like he is going to die like he did in the past.