Kowakubi Onsen Shohoen

Shohoen stands alone beside the Omono River in Kowakubi, Daisen City, Akita Prefecture. The building was completed in 1917 as the main residence of the Oyamada family, major landowners who held some 450 hectares of surrounding farmland since the Edo period. This two-story wooden mansion features a karahafu gabled entrance, a Rokumeikan-style staircase hall, and a corridor floored with a single 16.3-meter plank of natural Akita cedar. It is listed as a Registered Tangible Cultural Property of Japan, and has operated as an inn since 1966. It is also a member of the Japan Association of Secluded Hot Spring Inns.

Hot water was first struck here in 1964 during test drilling for natural gas. In February 2008 the inn succeeded in drilling its own well on the property, which flows without pumping at 246 liters per minute and 49 degrees Celsius. The spring, named Shohoen-no-Yu, is a rare iodine-bearing sodium chloride strong salt spring with a source temperature of about 49.8 degrees Celsius, pH 6.9, and a total dissolved solids content of 22.24 grams per kilogram. The cloudy brown water carries flakes of mineral deposit and is delivered to every bath as free-flowing source water, with no added water and no reheating.

Bathing facilities consist of a large indoor bath built entirely of hinoki cypress, plus two private open-air baths, Taiju-no-Yu and Komorebi-no-Yu, added in March 2008 and reserved for overnight guests. There are only seven guest rooms, priced from 17,750 to 25,450 yen per person with two meals. Day-trip bathing runs from 11:00 to 18:00 (last entry 17:00) at 650 yen for junior high school age and above, 350 yen for elementary school age and below.