It's not so much how I see it as it is the fact that this is ultimately written as a romance story, meaning this is a forever, lifetime relationship unless the author says otherwise (which she hasn't). So yes, in their world, Jiwon and Donggyun will develop a lifetime relationship (this is further confirmed by the last few panels of chapter 70, they've already developed that sort of emotional, almost familial, bond based on how they connect with each other's past difficulties).
However, in real life, not only would this not be a lifetime relationship, everything in the story would be perceived very differently.
True.
Do you see a lifetime relationship developing between Jiwon and DG?...or....Do you think at some point they will go their separate ways?