Eun-joo moves out of her house "Il Mare", leaving behind a Christmas card for the eventual new owner of the house in 1999. In it she asks him/her to forward any mail of hers to her new address in the city. It is 1997 and Sung-hyun, the first owner of "Il Mare" is moving in and finds in his mailbox the Christmas card from Eun-joo. Thinking it was a joke, Sung-hyun leaves her a letter telling her so and reminds her that its 1997 not 1999. Eventually the two realize that they are separated by two years of time but can somehow communicate through the mailbox and begin to form a friendship through their letters.