When Jongin decided to finally clean up his dirty attic, he was surprised to see a small battered and old box lying at the corner of the room.

The moment he opened up the box, he was able to peer into the letters written by a young boy named Do Kyungsoo.

Letters written a day and a year into the future. It took Jongin one hundred love letters from the future to make him realize that love was everywhere. Even in the worn out pages of long lost forgotten love letters.