This bill directs the State Department and Defense Department to engage with Japan about joining Pillar Two of the AUKUS partnership, which focuses on advanced military technologies like hypersonic weapons, cyber capabilities, and quantum computing. Within 90 days, U.S. coordinators must meet with Japanese officials to discuss their export control systems, identify areas where Japan could contribute to AUKUS projects, and assess whether Japan adequately protects sensitive defense information and enforces controls on technology exports to China. The bill requires a briefing to Congress within 30 days of these initial discussions and mandates a comprehensive report within 180 days assessing Japan's readiness to participate, potential areas of cooperation, and any reforms Japan may need to undertake. The legislation reflects Congress's view that Japan, as a technologically advanced treaty ally, could significantly contribute to advanced defense capabilities in the Indo-Pacific region alongside Australia and the United Kingdom.