The story is a little confusing at first, and it took me some time to (kinda) realize what's going on between the characters though this could have been due to my own weakness at comprehending what is going on.
What I figure is going on is that Ray breaks up with Don because he (Ray) is going overseas to study and he's trying to change Don for the better by pushing him to be more driven and independent so that his full potential will be unleashed. The couple work in the same advertising company, and Ray enlists the help of Lin (a colleague) to pretend to be his girlfriend and trigger Don's jealousy or something. (I'm not sure if I get the logic entirely because I don't know what breaking up with Don and pretending to have a girlfriend has got to do with changing Don for the better or Ray's plans to go overseas.) If we see more background about Ray and Don's relationship from the start and if we know about Ray's motivations earlier, the story will be be more moving. Unfortunately, the focus at the start is on lighthearted and funny moments (or what I thought were meant to be funny moments) that don't end up being all that entertaining. I also wish that the characters were better developed--Don is supposed to be a somewhat childish but certainly talented person but we don't see this quite clearly. Neither do we see how the break-up with Ray has affected him. Similarly, there could have been more depth to Lin: she's in love with Ray, but when did she fall in love with him and why did she agree to pretend to be his girlfriend?
We can't ask for too much in 40 minutes, but it isn't impossible to have more. Nevertheless, it's still a fairly watchable short movie that probably won't get on anyone's nerves