In my opinion, the most impressive scene is when Woosung fallen into water, it's definitely the killing part of the music video. When I see this scene, what I was thinking is just like what Woosung was singing "Okkk you're killing me. I am falling too" lol 

If we took this scene as a boy fall in love and the water represent a relationship. At first, when he is under water, he looks painful. But in the last scene, Woosung is sleeping peacefully under the water which makes me feel that this boy finally find his place and his happiness in the end.^^