The title, Il Mare, means "The Sea" in Italian, and is the name of the seaside house which is the setting of the story.

After some tests, they discover that the mailbox at Il Mare is enabling their communication and they can pass objects and living creatures through it.

After reading the book, Sung-hyun finally accepts his father's love for him and takes up architectural work once more.

Eun-joo asked for him, but learns that Sung-Hyun died in a traffic accident while meeting a friend two years ago.

She realizes that on the day she last met her fiancé before they separated, she witnessed a car hitting and killing a pedestrian.

The final scene returns to the beginning of the movie, where Eun-joo is about to place her Christmas card into the mailbox at Il Mare.

[3][4] This time-travel romance was not a popular success in 2000, selling less than a quarter million tickets in Seoul (upstaged by not only the similar-themed Ditto, but also the controversial Lies), but since then it has developed a loyal fan base a la Somewhere in Time and attained the status of a minor classic among Korean cinema fans.

[5] Warner Brothers acquired the rights for an American remake, titled The Lake House, starring Keanu Reeves and Sandra Bullock.

To reference the original movie, "Il Mare" was used as the restaurant's name where Kate and Alex are supposed to meet.