SB Intuitions, a SoftBank Group company, has initiated joint research with Juntendo University, SoftBank, and medical data platform provider HEMILLIONS starting in June 2026. The project uses "Med-Sarashina," a domestically developed generative AI for medical applications, aiming to improve the clinical reasoning capabilities of resident physicians and streamline medical education. Juntendo University will provide clinical insights and case data for medical education to train the AI, which is based on a domestic LLM developed from scratch by SB Intuitions, with additional training and fine-tuning using this medical data. The partners will develop prototype tools for diagnostic support and medical document creation. SoftBank will support, verify, and evaluate the AI model for practical application and explore business models. HEMILLIONS will provide a medical data platform complying with the "Three-Ministry Two-Guideline," safety management guidelines established by Japan's Ministry of Health, Labour and Welfare; Ministry of Internal Affairs and Communications; and Ministry of Economy, Trade and Industry. Med-Sarashina, built on this platform, is a domestic LLM independent of foreign foundation models, ensuring high safety in clinical settings and accommodating Japan's medical regulations. The research will also use post-training with medical data and knowledge graphs to develop tools for enhancing residents' clinical reasoning and improving medical education efficiency.