Terms of Service

1. Agreement to these terms

Koboshi (“Koboshi”, “we”, “us”) is a vocabulary-learning application operated by 〔legal entity / operator name — to be confirmed〕. By creating an account or using the service in any way, you agree to be bound by these Terms of Service and by ourPrivacy Policy. If you do not agree, do not use Koboshi.

2. What Koboshi is

Koboshi is a tool that helps you look up, save, and review vocabulary across multiple languages, using spaced-repetition scheduling and AI-assisted word lookups. It is a study aid, not a substitute for a qualified teacher, a certified translator, or professional language certification.

3. Who can use Koboshi

You must be at least 16 years old, or the minimum age of digital consent in your country, to use Koboshi. If you are under the age required to consent on your own, you may only use the service with the involvement of a parent or legal guardian. By using Koboshi you confirm that you meet these requirements and that the information you give us is accurate.

4. Your account

You sign in through Google or an email magic link. You are responsible for keeping access to your account secure and for all activity that happens under it. Tell us promptly if you believe someone else has accessed your account. We are not liable for losses caused by someone using your account because you failed to keep your sign-in method secure.

5. Acceptable use

You agree not to:

• use Koboshi for any unlawful purpose or in breach of these terms;
• attempt to access, probe, or scan accounts, systems, or data that are not yours, or bypass any authentication, rate limit, or usage cap;
• automate, script, scrape, or otherwise generate a volume of requests beyond normal personal study — including hammering the lookup or audio features to exhaust our AI or text-to-speech quota;
• upload content that is illegal, infringing, abusive, or that contains malware;
• reverse-engineer, resell, or commercially exploit the service without our written permission;
• interfere with the service’s operation or with other users’ use of it.

We may apply usage limits, throttle requests, or suspend accounts that we reasonably believe are abusing the service or putting it at risk.

6. Your content and data

The words you save, your notes, your study history, and any journal entries are yours. You grant us a limited licence to store and process that content only as needed to provide the service to you (for example, to schedule reviews, generate lookups, and display your library). Our handling of your personal data is described in the Privacy Policy. We do not sell your personal journal content.

7. AI-generated content — accuracy disclaimer

Koboshi uses artificial intelligence to generate word translations, meanings, example sentences, and related learning material. AI output can be incomplete, outdated, or simply wrong.Translations and definitions are provided for learning purposes only and are not guaranteed to be accurate, appropriate for every context, or fit for any official, legal, medical, or professional use. Always verify important information with an authoritative source. You use AI-generated content at your own discretion and risk.

8. Our intellectual property

The Koboshi name, logo, design, software, and the underlying spaced-repetition and concept-linking systems are owned by us or our licensors and are protected by intellectual-property law. These terms do not give you any right to use our branding or to copy the service except as expressly permitted.

9. Third-party services

Koboshi relies on third-party providers to function — including cloud hosting, database and authentication services, AI language models, and text-to-speech. Your use of Koboshi may be subject to those providers’ own terms, and we are not responsible for their acts or omissions. We list the main providers in our Privacy Policy.

10. Availability and changes to the service

We work to keep Koboshi available and reliable, but we provide it on an “as available” basis. We may add, change, suspend, or discontinue features at any time, and the service may be unavailable during maintenance or due to factors outside our control. We are not liable for any loss caused by downtime or by changes to features.

11. Disclaimers

To the fullest extent permitted by law, Koboshi is provided “as is” and “as available”, without warranties of any kind, whether express or implied, including any implied warranties of merchantability, fitness for a particular purpose, accuracy, or non-infringement. We do not warrant that the service will be uninterrupted, error-free, secure, or that any content or translation is accurate or complete.

12. Limitation of liability

To the fullest extent permitted by law, Koboshi and the people who operate it will not be liable for any indirect, incidental, special, consequential, or punitive damages, or for any loss of data, profits, or goodwill, arising from your use of (or inability to use) the service. Where liability cannot be excluded, our total liability to you for all claims is limited to the greater of the amount you paid us in the 12 months before the claim, or 〔JPY 5,000 / a nominal amount — to be confirmed with legal counsel〕. Some jurisdictions do not allow certain limitations, so some of these may not apply to you.

13. Indemnification

You agree to indemnify and hold us harmless from claims, damages, and expenses (including reasonable legal fees) arising out of your misuse of the service, your breach of these terms, or your violation of any law or third-party right.

14. Termination

You may stop using Koboshi and delete your account at any time. We may suspend or terminate your access if you breach these terms or use the service in a way that creates risk or legal exposure for us or others. On termination, the provisions that by their nature should survive (such as intellectual property, disclaimers, and limitation of liability) will continue to apply.

15. Changes to these terms

We may update these terms from time to time. When we make material changes, we will update the “Last updated” date and, where appropriate, notify you in the app. Continuing to use Koboshi after a change means you accept the updated terms.

16. Governing law and disputes

These terms are governed by the laws of 〔Japan — to be confirmed with legal counsel〕, without regard to conflict-of-law rules. Any dispute will be subject to the exclusive jurisdiction of the courts of 〔Tokyo, Japan — to be confirmed〕, except where mandatory consumer-protection law gives you the right to bring a claim elsewhere.

17. Contact

Questions about these terms? Contact us at 〔support@koboshi.app — to be confirmed〕.