The book "Law and Custom in Korea" explores how Korea's legal system changed over time, from the Chosǒn dynasty to modern times. It compares Korean legal history with European legal history, focusing on customary law. During Japanese rule, Korea shifted from its traditional legal system to a new civil law system. Japanese colonial jurists created a Korean customary law to bridge the gap between tradition and modern law. This transformation of Korean law shows how Western influences shaped the country's legal system. The book also discusses French customary law and Japanese legal history, providing a framework for comparing European and East Asian legal traditions.