Terms of use

Last updated: 3 October 2026 (takes effect on 10 October 2026)

Changes in the 3 October 2026 revision: Article 6 now names the components that PDFium incorporates, and states that these terms do not restrict anything the open-source licences permit. No other article has changed.

These terms set out the conditions for using Washi (the "App"). Washi is one of the services provided by tanmen.work, and these terms are service-specific terms sitting under the tanmen.work Terms of Service (the "General Terms").

This English text is a translation provided for convenience. The Japanese version is the authoritative text; where the two differ, the Japanese version prevails.

Article 1 (Relationship to the General Terms)

  • Using the App is subject to the General Terms in addition to these terms. Anything not covered here is governed by the General Terms.
  • Where these terms and the General Terms differ, these terms prevail (General Terms, Article 1).
  • If these terms change, the new text and the date it takes effect will be posted on this page, following Article 13 of the General Terms.

Article 2 (Licence)

  • We grant you a non-exclusive, non-transferable right to use the App under these terms and the General Terms. There is no limit on the number of machines, and neither personal nor work use needs any separate permission.
  • Rights in the App remain with us or the rightful owners. These terms transfer none of them to you.
  • Prohibited conduct — modification, decompilation, redistribution and the like — is set out in Article 6 of the General Terms.

Article 3 (How it is distributed)

  • The App is distributed through the Microsoft Store. If you obtained it there, the Microsoft Store terms set by Microsoft apply as well.
  • In these terms, "the App" means the copy we distribute through the Microsoft Store. Copies modified or redistributed by anyone else are not the App.

Article 4 (Price)

  • The App is free. There are no in-app purchases and no paid features.
  • If a paid element is ever introduced, it will be announced on this page and on tanmen.work beforehand. A copy you already have will never be charged for retroactively.

Article 5 (Data the App handles)

  • The App reads the PDF files you open, purely in order to draw them on screen. It never sends their contents anywhere.
  • The App makes no outside connections at all. There is no account, no telemetry, not even an update check.
  • What it keeps on your machine is the settings and an error log, and nothing more. The Washi privacy policy has the detail.
  • For the App, the Washi privacy policy governs. For the tanmen.work site itself — using the support desk, for instance — the tanmen.work privacy policy governs.

Article 6 (Third-party software)

  • The App includes the open-source software below. Copyright remains with the respective holders, and it is used under the terms of each licence. The full licence texts are in the third-party notices.
  • PDFium in turn incorporates FreeType, zlib, libjpeg-turbo, OpenJPEG, Little CMS, Anti-Grain Geometry, HarfBuzz, Abseil, ICU, fast_float, dragonbox, libc++, and llvm-libc, so these are part of the App as well. Their full licence texts are also in the third-party notices.
  • Nothing in these terms or the General Terms, including the prohibitions in Article 6 of the General Terms, restricts anything that the licence of each piece of open-source software listed in this article permits you to do.

Article 7 (Contact)

  • Questions about these terms, and bug reports for the App, go here.

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