Actually, Hajun is partially at fault. Since he couldn't remember everything that day, whe...

Actually, Hajun is partially at fault. Since he couldn't remember everything that day, when he heard the name Yunjae, he had assumed it was the blond guy, who surprisingly had the same name. Also, Hajun remembers the blood on the kid's sleeve, thinking that the kid might have hurt himself so when he saw the scar on the blond's arm, he really believed it was him. He felt infatuated towards the blond and the blond guy did develop feelings for him, not really sure but I think towards the end, he had a talk with Hajun and they discussed about the whole mistaken identity part. Also, Candy still doesn't know he is the kid. There is still a question on how he became an agent too and from what I understood from the raws, he was removed as an agent (not sure about this part) and uno became number one. Also, during the time Hajun was shot, his father was actually there but instead of helping his son, he fled away.