Chairman of Byungmoon Foundatgion & Byungmoon High and Yena's mother. Myung-joo is fiercely devoted to her school and daughter, believing they belong to her and must always be the best. Cold and calculating, she is Hae-sung’s greatest adversary, always steps ahead. She has long known his true identity and was the one who orchestrated the NIS mission to find the school's hidden gold.