Synopsis
The story begins at the tail end of 1999, as voiceover actress Eun-joo (Jun Ji-hyun) moves out of a seaside home named 'Il Mare'. Before leaving, Eun-joo leaves a Christmas card in the mailbox, with a message asking the eventual new owner to forward any mail of hers to her new address in the city. Meanwhile, exactly two years prior in 1997, Il Mare's first owner, architect Sung-hyun (Lee Jung-jae, who recently co-starred opposite Shim Eun-ha in "The Interview"), receives Eun-joo's card. Thinking it to be a joke, he writes back to Eun-joo and asks her not to tamper with his mailbox anymore, while pointing out that the 'current year' is 1997.