I was flying to Thailand with Turkish Airlines and saw this Asian movie. I believe it is either Japanese or South Korean. The movie isn't on the airline's movie list any more. I remember that the title had the word "love" in it, and I think it only had two words in the title. Unfortunately, I could not find a matching movie with my search.
In the film, a girl and a boy are dating each other. The boy gets a job in a bigger city, so he moves. Every weekend, he drives back to see his girlfriend (at the beginning).
But he meets someone else at work (they start dating), and the original girlfriend also starts to date this really shy guy. However this "shy guy" falls in love with her and tries to change himself to be more appealing to her.
The movie does not reveal that she is dating this guy and has a boyfriend working in the capital. It is not until the end that it is revealed that she started to date this guy.
The movie is made really well, giving this impression that both of the guys are the same person until the very end.