Yasudaya Inn

安田屋旅館やすだやりょかん

Lodging
Chubu·Shizuoka

Day Use

Yes

Bathing & Water

OnsenYes

Uses natural hot spring water

原保温泉 原保1号

Harubo Onsen Spring No. 1
Sampled at wellhead
Simple
Classification

Sodium Carbonate-Bicarbonate spring

A simple-type cold mineral spring that qualifies as an onsen on the strength of its metasilicic acid rather than any therapeutic anion. At pH 9.2 it is genuinely alkaline, giving the slippery, soft feel of Japan's beauty-water family. It carries 70.4 mg/kg of metasilicic acid, which leaves a thin silica film that makes skin feel smoother. Lightly mineralized and gentle on the body, and being a cold mineral source at 24.8 °C it is reheated for bathing.

pH
9.20
Alkaline
Source temperature
24.8°C
Cold mineral
Tonicity
0.17g/kg
Hypotonic
Flow rate
164L/min
Typical
Color
almost colorless and transparent
Taste
tasteless
Odor
odorless
Highlights
  • High silica
  • Cold mineral
  • Top-decile alkaline

Analyzed Mar 1, 2017·一般財団法人静岡県生活科学検査センター·Cert no. 第 M16047 号

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SM
Sergey M
1 year ago

508. Yasudaya Inn, Numazu, Shizuoka ★ Visited for higaeri at 1000 yen. Higaeri available from 12:00 to 14:00 and 18:00 to 20:00. They stamp the ICOI Project x Love Live! Sunshine temporary stamp rally. Had a cool story with foreigners here. After the onsen, I'm sitting in the ryokan lobby. Two Asian guys (not Japanese) walk in and ask in broken English if there's a shower. The staff guy also doesn't speak great English and this awkward situation starts with obvious miscommunication — they'd probably just get turned away. So I stepped in and sold them on the higaeri onsen. Then the staff guy tries to explain where to go, and it's not super obvious. So I ended up leading them there myself, showed them everything, explained how to take an onsen. Went back to reception, grabbed some tea and put down money, and the reception guy pushes the money back and says "service." Small outdoor stone bath. The view is more of an inner garden with trees and red maples. Got momiji in May. Clear water, temperature 39-40. Indoor bath with clear water, temperature 40-41. Red maple visible from the window too. Breathing inside is good. The ryokan itself looks interesting, baths are decent. Plus the bonus of momiji in May from the rotenburo. Pleasant place to be. 09.05.2025