Kurabuchi Aimagawa Onsen Fureaikan

An exceptionally concentrated hypertonic spring: ochre/brown, opaque (two reviewers warn you cannot see submerged steps), salty like seawater, iron-rich, with an oil smell and visible oil film on the surface. One reviewer cites total ions over 20,000; three call it hypertonic (koucho-sei); at least four mention the kerosene/oxidized-oil odor and two the glittering oil film; one notes towels come away stained yellow. Iron presence is agreed by at least four reviewers, though two say they could not actually smell the iron. One likens it to Toyotomi Onsen in Hokkaido, another rates it above Ikaho.

Two-tier pricing: Takasaki citizens pay 320 yen including bath tax (two reviewers, 2026; one adds no ID was required). Non-citizens: one Sep 2025 reviewer paid 540 yen, one Jun 2026 reviewer says 520 yen — the two figures differ, so the exact current non-resident price is uncertain but is roughly 520-540 yen. One reviewer notes discount coupons are available at a nearby roadside station. Reviewers repeatedly call it very cheap for the water quality.

Yuatari (bath sickness) risk is real and officially flagged: reception instructs bathers to get out after about 7 minutes and hydrate (one reviewer), posted notices warn about yuatari (one reviewer), and two more reviewers independently warn the water overwhelms within about 10 minutes or is easy to get overheated in because it does not feel hot. Multiple reviewers report unusually long-lasting warmth and sweating after bathing.

One indoor bath and one outdoor bath, both modest in size (two reviewers say neither is large; one calls them mid-sized with 5+ washing stations). Reported temperatures: one July 2026 visitor says both were set to 42°C (too hot for his children); one Jan 2026 visitor measured indoor 41.5°C and rotenburo slightly cooler at 41°C; another says indoor hot, rotenburo lukewarm. No reviewer mentions a sauna.

One reviewer (Jul 2025) states operating hours of 10:30-19:00. The dining room serves lunch 12:00-14:00 (one reviewer; another confirms lunch ends at 14:00, with the signature kamameshi taking about 30 minutes to prepare). It stayed open through the New Year period (open through Jan 5 per one Jan 2026 visitor). Day-use and overnight stays both operate.

Amenities are minimal but free: bath area has only bottles labeled 'hair' and 'skin' (one reviewer) — another calls it rinse-in shampoo — the changing room has 2 hair dryers and tissues only, and both shoe boxes and changing-room lockers lock without needing any coin (two reviewers). Practical note from one reviewer: the ochre water stains towels yellow, so bring a towel you don't mind discoloring.