Osuge Onsen Satomiya Ryokan

Osuge Onsen Satomiya Ryokan is a mountain mineral-spring inn in Osuge-cho, Hitachiota City, Ibaraki Prefecture, in a corner of the Okukuji hot spring region. It sits in a quiet valley overlooking the Sato River, a tributary of the Kuji River, surrounded by deep forested hills. The waters of Osuge have served as a healing bath for roughly 300 years, with the spring said to have been discovered in 1781.

The spring is classified as a simple sulfur spring, drawn from the source known as Osuge Kosen. Its smooth, sulfur-bearing water is traditionally valued for neuralgia, rheumatism, sensitivity to cold, and skin ailments. Because the source emerges as a cold mineral spring, the water is heated before being supplied to the baths, which include a distinctive lion-shaped spout.

The bathhouse offers an indoor bath and an open-air bath, and quiet hours can feel almost like a private soak. Day-trip bathing costs 600 yen for adults and is available from 10:00 to 16:00, though holidays are irregular and day use may be unavailable when the inn hosts groups, so calling ahead is recommended. Overnight stays start from 7,850 yen with two meals, featuring river fish, mountain vegetables, hand-cut soba and udon, and wild-boar hot pot in winter.