Tokachigawa Onsen Sasai Hotel

Sasai Hotel bathes in Tokachigawa's moor onsen, a plant-derived spring whose peat gives the water an amber tint and a smooth, mild feel on the skin, kept flowing fresh from the source. The large baths are split for men and women and mix indoor and outdoor options, including a hinoki wood tub, a round jar bath (tsubo-buro, つぼ風呂), a jet bath, and a waterfall bath (utase-yu, 打たせ湯), plus a sauna and a cold plunge. Day-use bathing runs from early afternoon into the evening. The hotel's own history traces back to 1900, when the first bath that founded Tokachigawa Onsen was built here, and by 1913 it had grown into a ryokan called Sasai, one of the oldest in the district. Parts of the building and the dining hall have been renovated over the years, and guests often mention a genuinely old-style stay (tatami-floored changing rooms included) that stays quiet even when the hotel is busy with tour groups.