Onomichi Fureai no Sato Natural Hot Spring

Onomichi Fureai no Sato stands on a hillside at about 150 metres above sea level in Takao, Mitsugi-cho, roughly 25 minutes inland from central Onomichi in Hiroshima Prefecture. Known as the back parlour of Onomichi, the Mitsugi valley surrounds the inn with rice paddies and cedar forest, and the baths look out on a night sky far darker than the coast allows. The publicly backed operator, Mitsugi Koryukan Co., was founded in 2002, and the hot spring inn itself opened on 11 March 2006, marking its twentieth anniversary in 2026.

The water is classified as a simple weak radioactive cold mineral spring, drawn from the inn's own well 800 metres underground at a generous 300 litres per minute. It emerges at 21.0 degrees Celsius with a pH of 8.7, colourless, clear and odourless, and carries 11.3 Mache units of radon per kilogram, well above the 5.5 unit threshold set by the Hot Spring Law. Because the source is below 25 degrees, most tubs are heated and filtered through a circulation system, but the inn explicitly advertises dedicated source-fed tubs, and both the indoor and open-air areas include an unheated free-flowing bath.

Two bathing wings, Fureai no Yu and Hohoemi no Yu, alternate between men and women each day. Between them they offer thirteen kinds of bath, including rock-built open-air tubs, a far-infrared sauna, a cold plunge, a walking bath, a foot bath and a plasma bath said to be the only one in western Japan. Day bathing runs 10:00 to 22:00 with last entry at 21:30, costing 850 yen for adults on weekdays and 900 yen on weekends and holidays, 500 yen for elementary school children and free for under-threes. The inn has 23 Japanese-style rooms, 42 Western-style rooms and one accessible room, sleeping up to 140 guests, with free parking for about 450 cars.