Cases of Japanese spotted fever (JSF) have been reported mainly in the warm southwest region of Japan. A woman in her 40s developed a fever after being bitten by a tick attached to her pet dog in Hyogo Prefecture (west Japan). She then traveled to a vacation home in Yamanashi Prefecture (central Japan). Though she sought medical care in both prefectures, her symptoms did not improve, so she was admitted to our hospital, which is located in Nagano Prefecture near her vacation house. She had high fever and eruptions and had developed acute disseminated intravascular coagulation. From an interview, we suspected tick-borne disease and administered doxycycline and levofloxacin. She subsequently recovered. Nine months after discharge, a serological test performed at the National Institute of Infectious Diseases in Tokyo confirmed a diagnosis of JSF. JSF is a rare disease in Nagano Prefecture, with only 3 cases reported from 1999 to June 2020. As shown by this case, we should consider JSF in the differential diagnosis of patients with acute high fever and eruptions regardless of geographic region, because unlimited travel across Japan is now common.