Dr. Yoon Hong Gyun serves as the director of Hong Gyun Yoon Psychiatry Clinic in Korea. A graduate of Chung-Ang University College of Medicine, he is renowned for his expertise in self-esteem and addiction. Raised in a large family of ten, Dr. Yoon became interested in interpersonal dynamics early on, sparking his interest in behavioral psychology. The Self-Esteem Class represents the culmination of his experiences and knowledge, aimed at addressing the concerns and questions of those seeking to better understand and transform their lives. It has quickly become a publishing phenomenon in Asia, with sales exceeding a million copies.