My memory of this movie is a bit vague, but it is about a young couple. The girl cannot make a commitment to the guy until she sorts something out and she can't tell the guy what the problem is. She tells him she has to go away but tells him to meet her at a special tree in a year ? She buries a box at the tree with a letter in it and tells him if she isn't there in a year that he should dig up the box and read the letter and it will explain.

Any help with this title greatly appreciated, its driving me nuts!

For anyone else trying to find the name of this movie it is My Sassy Girl