In this study, we report a new network system to facilitate functional cooperation between medical and long-term care providers in the progressively aging society of Japan.Currently, medical and long-term care resources are not sufficient to meet the needs of the entire population and this presents a very serious problem. Sado City, on Sado Island in Niigata Prefecture, has a remarkable aging society, with elders accounting for 36.8% of the population. This is because both the patients and medical staff are aging. To conserve the limited medical resources of the island, a new system for inter-regional medical cooperation was initiated in April 2013. In this network system, the patient’s diagnosis, prescription, treatment, examination, and imaging results can be shared with all medical institutions that are part of the system. Every participating medical institution can either opt to introduce the electronic medical records system or use an alternative recording system, because the data for this inter-regional medical cooperation is extracted from medical treatment fees data. Nursing facilities can also access the data. Nursing care staff have information on their patient’s activities of daily living, routine vital signs, and other important data. In December 2013, a new initiative was started where nursing staff can not only receive their patients’ data, but also send data such as those mentioned above. To achieve functional cooperation between medical and long-term care providers, it is important to have access to all data and to communicate openly. The established system easily and effectively facilitates communication among staff and participating institutions.