In this study, we attempt to reveal the relationship between the National Diet of Japan and Japanese ministries by text analysis of minutes data. The policy making process mainly consists of two routes: One is the parliamentary initiative route, and the other is the ministries initiative route, which is often consulted by advisory committees. These policy making process routes are not independent, but affect one another. While there are many studies and reports that have explored these relationships, most of them are qualitative case studies, which have some methodological limitations such as little comparability among cases.
We propose a method of measuring the relationship between the National Diet of Japan and Japanese ministries through text similarity and time stamps contained within minutes of public organizations, which have been published online, providing machine-readable open data. Our analysis suggests that the method draws consistent results with existing qualitative analyses and can effectively support and improve understanding of the relationship between the Diet and ministries. In addition, this method has an advantage of analyzing a wide variety of topics using the same method, ensuring comparability for researchers.