Dongwoo's story is probably the easiest since it didn't have too much symbolism and most of his story can be seen in plain sight.

Dongwoo's engaged. A happy couple, indeed, on the way to the hotel on a cold winter night until the dreaded accident happened.

What is this non-sense I speak of? I have three determinants as to why I am able to speak of such a sad story.

First, the ring which dongwoo held by a necklace chain. Just by this object, which dongwoo looked so lovingly and, obviously, adored, one will come to the conclusion that, yes, dongwoo was probably engaged if not married. Also, if you look at the number of rings, it has more than one. Probably, he removed his ring as well since he................. let's prolong the suspense.

Why were they a happy couple? Leads us to the second determinant. In all of dongwoo's scene, unlike the car which everyone noticed, one thing, one part, was probably subliminal to most of the mv's viewers. If you look closely, the car was in front of a place.... Try to remember... Where was the car parked? Bingo!! The car was parked in front of a hotel. Didn't notice that? That's okay. That's not what's significant here. Lmao jk. Anyways, Dongwoo was on the way to the hotel with his fiancee/wife and if you don't consider them a happy couple, I don't know who else is. 

The last determinant is the saddest and will definitely bring out the tears ((since I shed a few myself when I came up with this overanalysis)). Another subliminal part of the video. Watch closely. Isn't it pretty? Dongwoo's parts are really pretty because of those white things raining down on him. Oh wait... Come to think of it... What are those... Oh dear god... Woollim... YOU DID NOT. But yes, Woollim just did. Those pretty white things falling down on Dongwoo's beautiful perfection is what you think it is. Snow. Is it all snowing down on you now? 

To sum it all up.... Dongwoo WAS engaged/married to a girl, obviously. In Can't Get Over You, the happy couple's on their way to a hotel on a cold winter December night with Dongwoo behind the wheel (as seen at the very start of the mv) until the accident happened. Because of the snow, that, probably, covered the car's windshield causing Dongwoo to lose sight of the way and, at the same time, the slippery road the snow caused as well, the girl died. Dongwoo, therefore, was left alone to suffer, blaming himself for the death of his beloved; forever cursing himself for being so reckless, forever left alone never to get over his beloved's death since he constantly told himself that it was his fault. You know like all those car accident stories that break your heart, only this is worse since Dongwoo was the one left alone. 

If all these weren't bothering enough, let me give you something to think about... If you look at Dongwoo's car plate it says "NT7 0903", what do you think does this mean?