Shima Onsen Kashiwaya Ryokan

A 14-room retro-modern inn where three private open-air baths are free, unbooked and usable as often as you like, with a noon check-out — but it's a wooden house with steep stairs, no lift and thin walls, and most rooms have no bath of their own

Kashiwaya is a small two-storey wooden inn of 14 rooms at the entrance to Shima Onsen, fully renovated in 2021 in a nostalgic 'wa-modern' style — black dial phones in the rooms, stained glass in the women's bath, a library with free house-roasted coffee — and every room faces the Shima river. The draw is three private open-air baths that cost nothing and need no booking: check the lamps in the corridor, lock the door and stay about 30 minutes, as often as you like from 15:00 to 1:00 and 5:00 to 11:00. Check-out is a late 12:00. The water is Shima's sodium-calcium chloride-sulphate spring; the inn's own table lists only the barrel bath Tsuki-no-yu and the two rooms with open-air baths as fully free-flowing, the rest as free-flowing with recirculation, with up to about 4°C of heating. Japanese guests rate it 4.7 across 1,256 reviews on one major site (dinner 4.8, rooms lowest at 4.3), 4.59 across 570 on another and 4.46 across 47 on a third (baths 4.79). Reviews from 2022 to 2026 praise the warm, young, multinational staff, Jōshū beef stone-grilled at the table, a choice of Japanese, Western or café-brunch breakfast, fresh towels in every changing room and a soap-bubble send-off. The complaints are consistent: no lift and steep stairs, including up to the private baths; thin walls, with snoring, footsteps and bangs heard in 2024–2026; cold ground-floor rooms and changing rooms in winter; standard rooms without a bath or shower; uneven dishes; and a 20-minute walk to the village centre. An August 2026 two-night stay on a beef plan got no beef on the first night. Standard two-meal rates run about ¥21,000–34,000 per person for two, from ¥3,000 more on Saturdays.