(1) What I Lost

Xiumin has a little sister, Hajae. Living with them is Sung Hyojin, who is a very close friend of both, and next door is Kim Jongin, Kai. One day, Xiumin and Kai head to Seoul, and unlike usual, they don't return.

Over a year passes before they finally return. It turns out that the two joined a Korean band called Exo, which actually leads to not only love, but possibly the loss of a friend.

"You left me for more than a year, then you brought us here, and look where we are. It's YOUR fault."