Preventive healthcare is the linchpin of sustainable health systems, especially in aging societies like Japan. Chronic diseases are surging due to urbanization and lifestyle shifts, demanding a transition from reactive to proactive care. AI-powered diagnostics, early screenings, and digital health interventions must be integrated into national policies to enable timely interventions and reduce healthcare expenditures. Governments should mandate routine health screenings, incentivize healthy lifestyles through tax benefits, and expand AI-driven telemedicine. A robust data governance framework under Japan’s APPI and South Korea’s PIPA is essential to ensure privacy and ethical AI deployment. Public-private collaborations must scale digital health solutions, making preventive care more accessible and cost-effective. By embedding prevention into national healthcare strategies, Japan and East Asia can pioneer a global model for sustainable, proactive, and technology-driven healthcare.