Jackson was a gang leader; the bad boy that had always protected Mark.   Jinyoung was a transferee; the nice boy that was persistent in being Mark's friend.   They both loved Mark. They both hated each other. And when Mark's life was put into danger, they died for him.   Now as "angels of death" with no memories, they must collect souls in order to remember. One soul is equivalent to one recollection.   But what if along the way, Jackson