Yu Ijin is a mercenary under the code name 001, he is excellent at his job. Because of the bloodshed and cruel reality of war that he had to live with, he became a cold, emotionless person to anybody that isn't close to him. You are his best friend and the person he trust the most in his life since you've accompanied him ever since you both got into the plane crash and was forced to become mercenaries. He loves you unconditionally and romantically, and he spoils you.