Effective date: 2026-10-08

Operator: Zhang Yuanyi (individual developer, located in Japan; “we” or “us” in this document)

Copyright holder: Copyright in this software and its proprietary data is held, within mainland China, by 北京莫克波特科技合伙企业（有限合伙）(a limited partnership registered in Beijing, China), and outside mainland China by Zhang Yuanyi (individual, located in Japan). “Copyright holder” in Sections 3 and 4 means the rights holder for the territory in question.

Contact: [email protected]

Welcome to Tomoshi. Tomoshi is a Japanese-learning dictionary application comprising a desktop application and a companion browser extension (together, the “Software”), together with cloud services operated by us (speech synthesis, AI analysis, wordbook cloud sync and the like; the “Cloud Services”).

By downloading, installing or using the Software and the Cloud Services, you agree to these Terms. If you do not agree, please do not use them. These Terms together with the Tomoshi Privacy Policy (in-app under “Settings → Privacy Policy”, or on the website at https://tomoshi.app/privacy/) constitute the entire agreement between you and us.

1. Overview of the Service

  • Tomoshi’s core dictionary features run locally on your device and require no account registration;
  • Enhanced features such as pronunciation playback and AI analysis are provided by the Cloud Services, with usage managed through an anonymous device identifier; see the Privacy Policy for details. Wordbook cloud sync requires signing in with an email address (Section 5.3); nothing else requires signing in;
  • We currently provide the Software and the Cloud Services free of charge (see Section 8).

2. Eligibility

You must have the legal capacity required to use this service; minors should use it with the informed consent of a guardian.

3. Software Licence

The two components of the Software are licensed differently:

  • Desktop client: proprietary software; copyright is reserved by the copyright holder (see the “Copyright holder” entry above). The copyright holder grants you a free, non-exclusive, non-transferable licence to install and run it on your own devices. Without the copyright holder’s permission, you may not redistribute, sell or rent the client, provide commercial services to third parties based on it, or remove or alter any copyright or other rights notices it contains;
  • Browser extension: released as open source under the GNU Affero General Public License version 3 (AGPL-3.0). That licence grants you the right to use, study, modify and redistribute the extension, and these Terms neither restrict nor diminish any right the AGPL-3.0 grants you; rights and obligations at the level of the extension’s source code are governed by the text of that licence.

Please also note:

  • The “Tomoshi” name and logo are not covered by any of the licences above. When distributing a modified version of the extension, you may not use the name or logo in a way likely to cause confusion, or suggest that the modified version is published by us;
  • Third-party open-source components included in the Software are provided under their respective licences; the list is available in-app under “Settings → Open Source Licences” or on the website at https://tomoshi.app/licenses/ ;
  • The Cloud Services are not part of the Software: whether you use the official client or a modified one, access to the Cloud Services is governed by these Terms (see Section 5).

4. Dictionary Data and Content

The dictionary database bundled with the Software is composed of several layers:

  • Third-party open data layer (such as JMdict and KANJIDIC2) is provided under its respective licences (CC BY-SA and others); sources and licence details are available in-app under “Settings → Open Source Licences” or on the website at https://tomoshi.app/licenses/ . Reuse of this data is governed by the original licences;
  • Tomoshi’s own data layer comes in two parts:
    • The published part — content produced and edited under the copyright holder’s direction and released in the open data repository ( https://github.com/tomoshi-app/tomoshi-dict-data ): the Chinese glosses, translated sense notes, kanji variant notes, synonym-contrast cards, Chinese→Japanese word-choice cards, English→Japanese word-choice cards, transitivity pair cards and the like. It is provided under CC BY-SA 4.0: you may reuse it with attribution and under the same licence, as set out in that repository’s LICENSE and NOTICE;
    • The reserved part — content that is not published there: the Chinese and English reverse-lookup indexes, Chinese translations of example sentences, grammar points and their explanations, the verified layer of pitch-accent data, conversational frequency ranks and the like. Copyright is reserved by the copyright holder, and you are licensed to use it for personal study purposes within your use of the Software. Without permission, you may not extract it in bulk, compile and redistribute it, or use it to build a competing data product;
  • AI analysis results (generated on demand in the cloud) are likewise for your personal study use; results you choose to share are handled under Section 6.

5. Cloud Services

5.1 Quotas and Fair Use

The Cloud Services are subject to usage quotas (such as a daily number of AI analyses; the actual figures shown in the app govern). Quotas, rate limits and service parameters may be adjusted in line with cost and load; significant adjustments will be announced in the app or in the release notes.

5.2 Prohibited Conduct

When using the Cloud Services, you must not:

  • Circumvent quotas, rate limits or anti-abuse mechanisms by means of scripts, automation tools or a modified client;
  • Bulk-harvest or scrape the output of the Cloud Services, or resell or redistribute the Cloud Services to third parties;
  • Interfere with or disrupt the operation of the service, or probe or exploit its vulnerabilities (good-faith security reports excepted — please do get in touch through the feedback channel);
  • Use the service for unlawful purposes.

If you breach this Section, we may restrict or stop the relevant device’s access to the Cloud Services without notice; local dictionary functionality is unaffected.

5.3 Account and Sign-In (wordbook cloud sync)

  • Optional sign-in: every feature of the Software works without an account; only wordbook cloud sync requires signing in by email verification code. The rules for collecting, storing and deleting the email address are in Section 2.8 of the Privacy Policy;
  • Personal use: the account is for your own use and must not be lent or transferred;
  • Signed-in state: the sign-in is associated with the device you are using, is valid for 30 days and is renewed automatically; you may sign out at any time, which stops syncing and keeps your local wordbook;
  • Cloud copy: the wordbook and review progress synchronised to the server remain yours; we merely hold them so that your devices can stay in sync and use them for nothing else; you can export the whole wordbook in the app at any time;
  • Account deletion: you may delete your account at any time in the app under “Me / Settings → Account → Delete account”. Deletion takes effect immediately and cannot be undone — the server removes your email address, account record and wordbook cloud copy at once; your local wordbook, history and other data are unaffected. Signing in again creates a new account.

6. User Sharing and Feedback

  • Sharing analysis results: when you actively tap to share, you authorise us to add that AI analysis result to the shared cache and serve it to other users querying the same content. You may withdraw a share in the app, after which the result is no longer served to others;
  • User feedback: content you submit through the feedback channel (bug reports, suggestions and so on) is licensed to us, free of charge, for the purpose of improving the product, including revising dictionary data on the basis of it.

7. Content Accuracy and Disclaimer

  • All content in the Software (dictionary definitions, example sentences, grammar explanations, pronunciation, AI analysis and so on) is for language study reference only; we do not warrant that it is accurate, complete or consistent with any examination standard;
  • JLPT level labels are community estimates, not official data;
  • AI analysis is generated by a large language model and may contain errors or inaccuracies; please cross-check against authoritative sources;
  • To the maximum extent permitted by law, we accept no liability for any loss arising from reliance on the above content (including the consequences of using it in examination, translation, business or similar settings).

8. Free of Charge, Donations and Future Changes

  • The Software and the Cloud Services are currently provided free of charge; being free is not a commitment to continue providing them;
  • If you choose to donate, the donation is a gift without consideration: it unlocks no features, constitutes neither a purchase nor a service contract, and is in principle non-refundable;
  • If paid features are introduced in future, we will announce this in the app in advance and update these Terms; local features you already have will not stop working as a result.

9. Changes, Interruption and Termination of the Service

  • The Cloud Services are provided on an “as is” and “as available” basis; we do not warrant that they will be uninterrupted or error-free;
  • We may change, suspend or terminate some or all of the Cloud Services (for example because of changes at an upstream provider, or for cost reasons). Foreseeable permanent termination will be announced in advance in the app or in the release notes;
  • Termination of the Cloud Services does not affect your continued use of local dictionary functionality, nor any right you have in the browser extension’s source code under AGPL-3.0.

10. Limitation of Liability

To the maximum extent permitted by applicable law: the Software and the Cloud Services are provided as is, without warranty of any kind, express or implied; we accept no liability for indirect loss, data loss (including merge conflicts or loss during wordbook cloud sync — a local copy is always kept and you can export a backup at any time), loss of profit or the like; and in any dispute arising from a free service, our aggregate liability is limited to the amount you have actually paid to use the service (currently zero) or to the minimum permitted by law. This Section does not exclude any liability that may not be excluded by law.

11. Relationship to the Privacy Policy

How we handle data relating to you is set out in the Tomoshi Privacy Policy (in-app under “Settings → Privacy Policy”, or on the website at https://tomoshi.app/privacy/ ). The Privacy Policy forms part of these Terms.

12. Changes to These Terms

We may revise these Terms. When we do, we will update the effective date; substantive changes affecting your principal rights and obligations will be prominently notified in the app. Your continued use of the service after a change takes effect constitutes acceptance of the revised Terms.

13. Governing Law and Dispute Resolution

These Terms are governed by Japanese law. In the event of a dispute arising from these Terms or the service, the parties shall first seek to resolve it amicably; failing that, the Tokyo District Court (東京地方裁判所) shall have exclusive jurisdiction by agreement as the court of first instance.

14. Contact

For questions about these Terms, contact us through the in-app feedback channel or at [email protected].

15. Notice for Users in the EU (Digital Services Act)

This Section supplements these Terms for users and authorities in the European Union, as required by the EU Digital Services Act (Regulation (EU) 2022/2065, the “DSA”). Wordbook cloud sync stores content you provide on our servers (the entries you save, notes you write, names of wordbooks you create and similar), so the service is a hosting service within the meaning of the DSA. That content is used only to keep your own devices in sync and is never shown to other users or the public.

  • Single point of contact: our single point of contact for Member State authorities, the European Commission and the European Board for Digital Services (DSA Article 11) and for users (Article 12) is [email protected]. You may write in English, Chinese or Japanese. Messages are read and answered by a person, not solely by automated tools;
  • Legal representative (Article 13): we have appointed Data Protection Representative Limited (trading as DataRep) as our legal representative in the EU. Email [email protected] (quoting “Tomoshi / y1z” in the subject line); web form https://www.datarep.com/data-request ; telephone +353 1 919 8899; post DataRep, 77 Camden Street Lower, Dublin, D02 XE80, Ireland — address letters to “DataRep”, not “Tomoshi”, and state in the letter that it concerns Tomoshi.

15.2 Content Restrictions and How We Handle Content

  • Content you store through the cloud services must not breach EU or Member State law, and must not be used for any conduct prohibited under Section 5.2;
  • We do not proactively review content you store in the cloud, do not use automated tools to detect, filter or act on content, and do not use recommender systems. Content is reviewed manually, by us, only when we receive a notice under Section 15.3 or a lawful order from an authority, or become aware of a breach of Section 5.2;
  • Where a review finds content to be illegal or in breach of these Terms, we may remove that content, suspend or end wordbook cloud sync for the account, or restrict the device’s access to the cloud services under Section 5.2. Measures are proportionate to the severity of the breach, and data stored locally on your devices is unaffected;
  • When we take such a measure, unless the law prohibits it, we will tell you by email at your sign-in address what we did, the facts and reasons, the legal or contractual ground relied on, and the redress available to you (DSA Article 17). If you disagree, reply to that email or write to [email protected] and we will review the decision again; you may also seek redress before a court or competent authority.

15.3 Notices of Illegal Content

Any individual or entity who believes that content stored on the service is illegal may notify us by email at [email protected] (with “DSA notice” in the subject line). To help us act on it, please include:

  1. the reasons why you consider the content illegal;
  2. information sufficient to locate the content (for example the sign-in email of the account concerned and the exact wording of the entry or note);
  3. your name and email address (not required for notices concerning the offences referred to in Articles 3 to 7 of Directive 2011/93/EU);
  4. a statement confirming your good-faith belief that the information and allegations in the notice are accurate and complete.

We will confirm receipt, process the notice in a timely, diligent and objective manner, and inform you of our decision and the redress available; no automated means are used in processing notices (DSA Article 16). Inappropriate content in AI analysis results can also be reported directly with the “Report” button on the result card.

The Simplified Chinese version of these Terms is the original and governing version. This English version is provided for convenience only; in the event of any discrepancy between the two, the Simplified Chinese version prevails.