As a child, he was imprisoned in the Yodok concentration camp for 10 years. After his release he fled the country, first to China and eventually to South Korea. He is the author, with Pierre Rigoulot, of The Aquariums of Pyongyang and worked as a staff writer specialized in North Korean affairs for The Chosun Ilbo.
According to his autobiography, Kang was born in Pyongyang, North Korea, and spent his childhood there. He had a good relationship with his grandfather. He had a happy childhood. His grandfather was the Vice President of the Commercial Management office in Pyongyang, supervising all the commercial stores and department stores in Pyongyang. His grandmother was a member of the Supreme People’s Assembly and was the deputy head of the Workers’ Party organization of female members. She was deputy to Kim Il Sung’s wife. His family lived in relative luxury from his grandfather’s position and the fortune that he had given to the country upon the family’s return from Japan. Though they had never renounced their North Korean citizenship and Kang’s grandmother had been a staunch party member in both countries, Kang has stated that the family remained under a cloud of suspicion for having lived in Japan.