For those of you who are unclear about the meaning of the video, here's my interpretation: G-dragon was in a relationship with the chick we see at the beginning of the video. They obviously break up as she gives him back the ring. Later on, we see TOP in a car with the girl and G-dragon becomes obviously upset. In the last scene, the chick is at the hospital (supposedly she has cancer) and G-dragon rushes over and meets TOP who told him that he lied and she really loves him (G-dragon). She just passes away and G-dragon cries etc.
The lyrics and translation can be found here thanks to Korean Info Blog