In Japan's 2025 House of Councillors election, reducing the value-added tax (consumption tax) and distributing benefits became major issues. However, insufficient evidence regarding the structure of household burdens prevented proper evaluation of these proposals during the election. Recognizing this, this research project has two objectives. First, it aims to contribute to building a national consensus by conducting a data-based, cross-system analysis of the tax and social insurance burden on Japanese households. The second objective is to use the results of this analysis to clarify how households can be supported appropriately, propose concrete reforms to the tax and social security systems—including "tax credits with benefits" like the Earned Income Tax Credit—and facilitate the implementation of these systems in society. To achieve these objectives, we will conduct simulation analyses and other methods using individual-level panel data from the Japan Household Panel Survey (JHPS), which is implemented and collected by the Panel Data Research Center at Keio University. Existing cohort analyses by private research institutions are inaccurate regarding the burden structure of income tax, social insurance premiums, and consumption tax on Japanese households. JHPS individual-level data will be used to clarify the actual situation, as it enables more precise analysis tailored to analytical needs. We will then use these analytical results to promote understanding of household burden structures through communications from the Tokyo Foundation. Furthermore, we will examine desirable tax and benefit structures and formulate concrete policy recommendations by conducting microsimulation analyses of hypothetical system reforms using individual-level data.