This paper provides an overview of the R&D of AD technology in Japan and the efforts made towards its social implementation. It also reports that the long-term operation experiment of a Level 2 AD bus has been continuously conducted in the Kashiwa-no-ha area. This long-term operation has been realized with contributions from a diverse range of participants. It is also reported that improvements are being made sequentially to resolve issues learned in continued operation. Specifically, the introduction of Cooperative ITS service is described. Future challenges include verification of the use of the Cooperative ITS in actual operations toward the realization of Level 4 automated mobility service in Kashiwa-no-ha by the end of fiscal year 2025.