Higashi-Naruko Onsen Kuroyu no Takatomo Ryokan

Takatomo Ryokan is a traditional therapeutic hot spring inn (toji-yado) in the Washinosu district of Higashi-Naruko Onsen, the eastern gateway to the Naruko Onsen hot spring region in Osaki City, Miyagi Prefecture. It traces its founding to 1925. The main wing beside the road serves regular guests, while the annex added in 1977 has long been used as a self-catering wing for long-stay cure guests. The surrounding area once housed a bathing villa of the Sendai domain lords, and the inn stands about a three-minute walk from Naruko-Gotenyu Station on the JR Rikuu East Line. Among hot spring enthusiasts it is famous nationwide for its black water, and many regard it as one of Japan's finest springs.

The inn owns four private sources, all served free-flowing with no heating, no circulation filtering and no disinfection. The celebrated mixed-gender bath known as Kuroyu, the black bath, draws on the Sachi-no-Yu source: a sulfur-bearing sodium bicarbonate spring, hypotonic, neutral and hot, with a source temperature of 59.8 degrees Celsius, a pH of 6.8 and total dissolved solids of about 2,396 mg per kilogram. The water is so darkly clouded that it reads as black rather than dark green, and the bathhouse fills with a startling petroleum-like aroma reminiscent of tar or heavy oil. It is also described as the only iron-bearing natural radium spring in the Naruko region. The women's Ramune bath and the men's Hyotan bath use the Tama-no-Yu source, a sodium bicarbonate spring at 49.3 degrees Celsius with a pH of 6.5, notable for its roughly 45-degree bath temperature, brown mineral flakes and distinctly slippery feel. Two further sources, Washi-no-Yu for the family bath and Ken-no-Yu for the pool bath and Momiji bath, complete the lineup.

The inn is designed around four sources and seven tubs across one mixed bath, two women's baths, one men's bath and two private baths, but source trouble has limited recent operation to just three: Kuroyu, the Ramune bath and the Hyotan bath. All baths are indoors; there is no open-air bath. Day-trip bathing runs from 10:00 to 16:00 at 500 yen for adults and 250 yen for children, with free parking for about 50 cars. The interior is a genuinely retro cure-resort space that feels frozen in the Showa era, with a rest area and a dining room, and credit cards are not accepted. Overnight reservations cannot be made through online booking sites and the telephone is often unanswered, so confirming current operating status before visiting is essential.