Shima Onsen is a historic hot spring resort located in the mountains of Gunma Prefecture, approximately 150 kilometers northwest of Tokyo. The onsen town lies along the Shima River in the town of Nakanojo and has been welcoming visitors for over 1,000 years. According to legend, the springs were discovered in the Heian period (794-1185) when a deity appeared in a dream and revealed their healing properties. The name "Shima" refers to the belief that bathing in these waters can cure 40,000 ailments (shi-man means 40,000 in Japanese).
The town features approximately 40 traditional ryokan inns spread across four main areas: Shima, Onsen, Shinyu, and Yamanoue. The mineral-rich waters contain sodium calcium chloride sulfate and maintain a natural temperature between 40 and 60 degrees Celsius. Shima Onsen gained international recognition as the inspiration for the bathhouse in Studio Ghibli's film Spirited Away, with Sekizenkan Honkan ryokan particularly noted for its resemblance to the animated structure. This historic wooden bathhouse, built in 1691, features distinctive red lacquer architecture and is designated as a Nationally Registered Tangible Cultural Property.
Visitors can experience free public bathhouses scattered throughout the town, including the atmospheric Yakushido bathhouse near the Buddhist temple of the same name. The resort offers outdoor activities year-round, with hiking trails through cedar forests, fishing in the Shima River, and access to Okushima Lake, a scenic reservoir surrounded by mountains. Winter brings opportunities for nearby skiing at Naeba and Kagura ski resorts. The town maintains a quiet, traditional atmosphere with minimal commercial development, appealing to travelers seeking an authentic onsen experience.
Transportation from Tokyo requires taking the JR Joetsu Shinkansen to Jomokogen Station (approximately 70 minutes), followed by a 40-minute bus ride to Shima Onsen. Alternatively, visitors can take limited express trains to Nakanojo Station and transfer to a local bus for 40 minutes. Direct highway buses operate from Tokyo Station and Shinjuku during peak seasons. Most public bathhouses are free to enter, while day-use bathing at ryokan facilities typically costs between 500 and 1,500 yen. Overnight stays at traditional ryokan with meals included range from 15,000 to 40,000 yen per person.