Sukjoo Koh

Koh Sukjoo is the classmate, bodyguard, and secretary of Shin Yuna,the grand daughter of owner of the SW Corporation. He is shown to be protective of her, whether it be for business reasons or personal reasons. Koh takes his duties very seriously, and when Yuna got kidnapped, he blamed his own weakness. He has been trained from a very young age to protect and support Yuna. (Source: Mercenary Enrollment Wikia)