ONSEN RYOKAN YUEN SHINJUKU

Spring-source temperature

Not published for the water supplied to YUEN Shinjuku

Bathing temperature

Not published as a fixed value for the rooftop or suite baths

Spring source

Tsutsujino-yu at Odakyu Yama-no-Hotel in Hakone, transported to YUEN Shinjuku; from November 16, 2026, it is also used in four ONSEN Suite rooms

Spring classification

Alkaline simple spring (low-tonicity, alkaline, low-temperature spring)

pH

Not published for the water supplied to YUEN Shinjuku

Flow rate

Not published for the water supplied to YUEN Shinjuku

Water handling

Natural spring water is used in the 18th-floor outdoor bath only; the indoor bath is not an onsen. The hotel does not publish bath-by-bath water addition, heating, recirculation or disinfection details. The four ONSEN Suite rooms begin using the same source from November 16, 2026.

Analysis date

2026

The 18th-floor indoor bath is not natural spring water. The ONSEN Suite rooms do not begin stays until November 16, 2026. Public-bath hours change from November 1, 2026. Renovation work is scheduled through February 28, 2027, with possible noise and vibration from 11:00–15:00. Source and bath temperatures, pH, yield and tattoo rules for Shinjuku are not published.