The Taisho era (1911–1926) in Japan was a period marked by the penetration of mass culture and democracy. Thanks to the efforts of scholars like Takebe and Yoneda from the Meiji period, sociology was striving to catch up with international standards. In the global academic sphere of sociology, attempts were being made to address the following fundamental questions: What is the distinct subject matter of sociology? How should sociology be positioned among other social sciences? What exactly constitutes sociology? Yoneda categorized these issues into three types of sociology: organizational sociology, pure sociology, and synthetic sociology. The person who applied this to the analysis of actual society was Yasuma Takata, whom we will discuss in this chapter. Takata systematized these three fields of sociology—organizational sociology, pure sociology, and synthetic sociology—as defined by Yoneda and compiled them into a major work titled Shakaigaku Genri (Principles of Sociology). This achieved the long-cherished ambition of Japanese sociology to complete a comprehensive sociological system. Subsequently, Takata developed his ethnic theory by applying this sociology to practical issues. This meant that Japanese sociology had achieved the integration of pure theory (pure sociology) with a comprehensive understanding of real-world problems (synthetic sociology).