In Time You'll Love...

Jonghyun writes love letters to his beloved, Key. Although they live across the street from each other he could never bring himself to deliver them. Every time he was around Key the words never came out right, so he wrote the words he could never say down on some paper. Then he would go into town to mail them for 10 years. He became obsessed with winning over the heart of who he believes is his soulmate. Unknown to Jonghyun, the letters don't reach Kibum until 10 years later. When Kibum finally discovers the letters his marriage to Minho is in danger as he becomes torn apart by love.

http://www.asianfanfics.com/story/view/1099036