Japan's push to expand its renewable energy sector has become a central priority, driven by its advanced technology and industrial base and the need to reduce reliance on imported fossil fuels. This chapter explores the role of critical mineral imports—using Rare Earth Elements (REEs) as a representative indicator—foreign direct investment, income levels, and electricity consumption in shaping Japan's renewable energy landscape from 1990 to 2022. The findings suggest that while foreign direct investment presents challenges to immediate and sustained green growth; higher income levels play a supportive role in driving renewable energy development. REEs, although not immediately impactful, emerges as a vital factor for long-term green growth, highlighting the importance of strategic management and investment in this resource. Japan should focus on optimizing REEs utilization, strengthening regulatory frameworks, building domestic capabilities in REEs processing and recycling, and reducing its dependence on imported resources to ensure sustainable growth. These measures will be critical in advancing the country's transition to a more sustainable energy future while maintaining energy security.