This presentation discusses lessons learned from Japan's response to the 2011 earthquake and tsunami, known as the Great Eastern Japan Earthquake. It summarizes the large-scale disaster relief operation, called Operation Tomodachi, which involved over 20,000 personnel and ships and aircraft from the Japan Self-Defense Forces and US military. Key lessons identified include the need to enhance joint coordination between JSDF branches, improve transportation and logistics capabilities, tighten bilateral coordination with the US, and address challenges to Japan's defense industrial base from declining budgets. The presentation argues for reforms to strengthen jointness, transportation, logistics, and bilateral cooperation to respond effectively to future large-scale disasters.