I'm not sure if I should. Some people hate spoilers. And this revelation will come very late in the story.
@ShadowMadness
lol Yeah, there was a time when I feel sorry for him. Oh well, in every adaptation of this story, the adaptation changes the ending somewhat. So let's see how it goes.
@Aichan Just put it in spoiler tag for those who want to know lol
But because it has to do with siblings, maybe the Duan family are like long-lost cousins of whatever-her-name-was's family, and that they're actually (step?)siblings? That's my guess