Hakkei is a cuisine-focused ryokan located in Toyosaka, Maniwa City, Okayama Prefecture, within the Yubara Onsen district. Yubara Onsen is counted among Okayama Prefecture''s Three Great Hot Springs of Mimasaka (Yubara, Yunogo, and Okutsu), with a history stretching back approximately 1,700 years to the late Yayoi period. The renowned monk Shoku Shonin of Harima is said to have visited the area after receiving a divine revelation in a dream, and upon bathing in the waters, was cured of a serious illness, establishing the spring''s reputation as a medicinal bath. During the Warring States period, the warlord Ukita Hideie reportedly built a bathhouse here for his mother Lady Ofuku.

The spring quality is alkaline simple hot spring (low-tension, alkaline, high-temperature) with a pH of 9.3. The source temperature is 50.1 degrees Celsius, and the water is characterized by its colorless, transparent, odorless, and tasteless softness. The water is delivered as free-flowing source water, and even the guest room open-air baths and unit baths are fed with genuine hot spring water. The spring is renowned as a beauty bath with therapeutic benefits for neuralgia, muscle pain, joint pain, frozen shoulder, cold sensitivity, and fatigue recovery.

The inn features a variety of bathing facilities including the large public bath Kawa-no-Yu (River Bath) where guests can bathe while listening to the gentle sounds of the Asahi River, the private spa Sora-no-Yu (Sky Bath), the private indoor bath Nagomi-no-Yu, the barrier-free private bath Egao-no-Yu, and the private sauna Kaze-no-Yu. Directly in front of the inn lies the famous Sunayo, a free mixed-gender outdoor bath ranked as the Western Yokozuna (champion) in Japan''s national open-air bath rankings. The inn is celebrated for its mountain village cuisine featuring over 50 varieties of vegetables. All 32 guest rooms offer diverse room types including RE-Raku with twin beds, Ajisai with private open-air bath, and the barrier-free Kodachi.