Osawa Onsen Jisuibu Tojiya

Set in a river valley along the Toyosawa River in Yuguchi, Hanamaki City, Iwate Prefecture, Osawa Onsen is said to have been discovered around 1,200 years ago during the Heian period, when the general Sakanoue no Tamuramaro is said to have healed an arrow wound in its waters during a military campaign. Within the same grounds stand the modern ryokan Sansuikaku and the Jisuibu Tojiya, a self-catering lodge that still occupies a building more than 200 years old; it is the latter, steeped in the old culture of toji (therapeutic hot-spring stays), that is registered here. The poet and writer Kenji Miyazawa is also known to have visited frequently with his father as a boy.

The water is an alkaline simple hot spring (hypotonic) with a pH of around 9.0, a source temperature of about 51°C, and a flow rate of roughly 700 liters per minute, prized for its silky, gentle texture said to ease neuralgia, muscle pain, joint pain and stiff shoulders. The highlight is Osawa no Yu, a large mixed-gender open-air bath perched right beside the Toyosawa River, complemented by the women-only open-air bath Kawabe no Yu and the indoor, gender-separated Yakushi no Yu, among six baths in total across the property.

The Tojiya retains a communal kitchen where guests cook their own provisions on coin-operated gas stoves, while those who prefer not to self-cater can dine at the on-site restaurant Yahagi, known for local Iwate dishes and handmade soba. Day-trip bathing costs 700 yen for adults and 400 yen for children, open 7:00 to 20:30 year-round. Room-only stays start from 4,650 yen, still following the old-style toji pricing structure in which items such as yukata robes are billed separately.