We encountered a case of Japanese spotted fever in Unnan City, Shimane Prefecture. A 77-year-old woman visited our hospital complaining of fatigue. Initially, we diagnosed tsutsugamushi disease based on the constellation of presenting symptoms and clinical signs including fever, systemic erythema, and an eschar. However, the eschar was submitted for polymerase chain reaction analysis and was found to be positive for Rickettsia japonica. The final diagnosis was Japanese spotted fever. To the best of our knowledge, this is the first report of Japanese spotted fever in Unnan City, and there is a possibility that the condition has spread not only in the north of the prefecture but also in the south. This may be due to the widening habitat of ticks harboring R. japonica. Interestingly, the wild boar, a suspected vector, has expanded its habitat to the south of the prefecture. Research on the ecology of the wild boar is warranted.