Korean drama. Nuff' said.
Well, yes. But even a Korean drama committed to the endgame cliches, noble idiocy, time skip, coincidences, etc., would have at least answered the question, “Where have you been for more than a decade, MC, and why are you coming back now?”, and maybe given us a little bit more than a pair of shots that are just barely enough to determine that it is the returning lover, then a shot of a closing door.
I know that manhwa are getting notorious for abrupt and underdeveloped endings, but that was ridiculous even by WDTFS standards.