The Necklace

For Y/n's sixth birthday, Jimin gave her a heart-shaped necklace because they were best friends.
Immediately after her birthday, Jimin moved to Seoul in his mother's house , because his parents were divorced.
When Y/n was 16, her mother decided to remarry, because she was divorced from Y/n's father too.
Y/n could not accept it and through of fleeing to another city, but because she was still a minor she failed.
But BOOM, Y/n didn't know that her step-father is actually Jimin's biological father - her childhood best friend - she doesn't remember him because she was very young...