Fully OK
Mitsui Garden Hotel Shiodome Italia-gai
三井ガーデンホテル汐留イタリア街Main bath: OKOpen-air bath: OK
Official site · checked 16 Sep 2026 · see the wording Rates on booking sites
Details 15 places checked · 12 say yes (4 without conditions) · 3 unconfirmed · last check 16 Sep 2026
Tokyo is not a hot-spring town: most of what is sold as onsen here is a business hotel's large bath, water trucked in from Hakone or Yugawara, or a well drilled under an office block. The written answers split by owner, not by district — Mitsui Garden Hotels state they have dropped the restriction outright, Dormy Inn and APA hand out cover stickers at the front desk, and the independent hot-spring inns in Hinohara and Kamata say nothing at all.