A center device includes: an initialization request receiving unit that receives an initialization request for data stored on a vehicle side; an initialization target specifying unit that specifies initialization target data when the data initialization request is received by the initialization request receiving unit; an initialization campaign information distribution unit that distributes initialization campaign information corresponding to an initialization package for initializing the initialization target data; and an initialization package distribution unit that distributes the initialization package. A vehicle master device includes: an initialization campaign information receiving unit that receives the initialization campaign information from the center device; an initialization package receiving unit that receives the initialization package from the center device; and an initialization execution unit that initializes the initialization target data based on the initialization campaign information and the initialization package.