Ma Kwang-soo (마광수; 馬光洙; 14 April 1951 − 5 September 2017) was a South Korean poet, professor in Korean literature, novelist and essayist. He died in an apparent suicide in September 2017. For most of his life, he taught at Yonsei University. He was imprisoned for eight months, and discharged from his university for six years, for publishing 'sexually explicit' novels in 1995. His novel, Happy Sara (즐거운 사라) was deemed obscene by the Supreme Court and is banned for teenagers. In 2011, the author published a novel titled " A Letter of Crazy Words " and " Youth of Beautiful Youth. "