High cooling capacity and scalability of dilution refrigerators are essential for the realization of fault-tolerant universal quantum computers. To address these requirements, we have conducted research and development of complete dilution refrigerator systems, including pulse tube cryocoolers and sintered heat exchangers. We leveraged our group's expertise in vacuum engineering, cryogenics, and materials science to develop these systems. As part of the Moonshot Research & Development Program, we have constructed a dilution refrigerator system. In this talk, we will present our recent activities, including an overview of the system and the current status of our development of high-cooling-capacity dilution refrigerators.