I'm trying to find a movie I saw a few years ago, and I don't remember much about it so I hope someone will find with the few information I have
It's an asian ghost movie, a Korean movie I think, about a guy and his girlfriend. A lot of weird things happen to the guy, and the ghost who does that is (I think, I hope i'm not mixing different movies) a girl that used to love him, but that used to be bullied by him and his group of friends.
During all the movie, the guy has back pain and at a moment, he goes up on a scale and seems to weigh way too much.
In the end of the movie, he realizes that the ghost of the girl has been sat on his shoulders all along.
I know that's few information but I don't remember more than this, and since I saw this movie when I was younger and it scared me, I'd like to see it again now !