Oigami Onsen, Onsen resort in Tone, Numata, Japan

Oigami Onsen is a hot spring area nestled in the mountains of Gunma Prefecture near the Katashina River, surrounded by forest. The location features traditional inns with simple bathing facilities offering nature views, as well as a public bathhouse open to day visitors and overnight guests alike.

According to legend, the deity of Mount Akagi withdrew here after losing ground to the deity of Mount Futara and opened the spring by planting a bow in the ground, bathing his wounds before defeating his rival. The place name is linked to this tale, and the written form 老神 dates from the Eiroku era. Long known as a cure for skin ailments, it was visited by the poet Wakayama Bokusui in the Taisho era. In 1935 the inns of Oigami, Anahara and Oyang formed an association and named the area Oigami Onsenkyo; in 1959 the Sonohara Dam displaced four inns to higher ground and one was demolished.

The name Oigami derives from legends of a feud between the gods of Mount Akagi and Mount Futara; one theory links it to "Oigami" (追神, "chasing god"), another to a pun on "old body" made by the wife of Numata Castle's lord in the Eiroku era. The area has long been known as a therapeutic retreat for skin ailments, and today visitors can join events such as the February Setsubun festival with winter fireworks and the April–November morning market.

Buses from Numata Station take about 40 minutes; from Jomo-Kogen Station about 60 minutes, with only one round trip daily. In winter the bus bypasses the onsen, so alight at Ohara-Oigami Iriguchi or Shimo-Kaido and walk. By car, take the Numata Interchange of the Kan-Etsu Expressway and drive about 30 minutes on Route 120. Guests of the Sango, Awashima and Goro-kaku inns can book the free Jao-go shuttle by 16:00 the day before.

A special ticketing system called the 'yu-meguri tegata' allows visitors to visit three different bathing facilities in the area at a discounted rate. This pass system lets travelers sample multiple baths, each with its own distinct character, during a single visit.