Terms of Service

1. Service description

KuroNotes ("the Service") is a personal, monthly-subscription service providing note creation, storage, and cross-device sync using end-to-end encryption (E2EE). Note contents are decrypted only on the user's own device, and we cannot view their contents.

2. Account and key management

• Authentication uses passkeys (WebAuthn). Managing your passkeys and recovery code is your responsibility.
• If you lose every passkey and your recovery code, your data cannot be decrypted by anyone. We have no means of recovery.
• Accounts are intended for use by a single individual.

3. Pricing and contract

• Pricing is a monthly subscription (Japan: ¥100/month; pricing in other countries follows what is displayed in the store).
• Payment is processed only through the App Store / Google Play on the mobile app.
• Subscriptions renew automatically until cancelled. You can cancel via each store's subscription management. You may continue using the Service through the end of the current billing period after cancellation. We do not provide prorated refunds.

4. Data retention and automatic deletion (end-of-life)

After your contract ends, your data and account on our servers are automatically and permanently deleted once a set retention period has passed. Resuming your contract within the retention period keeps your data intact. Data cannot be restored after deletion.

5. Prohibited conduct

• Use for any purpose that violates law or public order and morals
• Acts that interfere with the operation of the Service (excessive load, exploiting vulnerabilities, etc.)
• Sharing or reselling your account

6. Disclaimer

• The Service is provided "as is." We bear no liability beyond the monthly fee for temporary unavailability caused by natural disasters, outages, or similar events.
• We bear no liability for data loss on your device or for being unable to decrypt data due to a lost key (data is also saved locally automatically, but backups remain your responsibility).

7. Consent to the contract and electronic records

• Starting a subscription requires agreeing to these Terms.
• When you agree, we electronically record and store the date and time of your agreement and the version number of the Terms in effect at that time. This record is used solely to evidence that the contract was formed.
• If the Terms are revised, we may ask you to re-agree to the revised version.

8. Usage statistics

To understand how the app is used, to find bugs and to improve the product, we collect only the following, anonymously:

• Number of app launches, total time spent in the app, and number of notes
• First-launch date, purchase date, operating system, and app version
• Error codes, such as those from a forced stop (a short identifier of the error type only — never the error message or stack trace)
• A random identifier generated on your device (used solely to avoid counting the same install twice)

This data is not linked to your account or to you as an individual. We never collect or look at note contents, titles, file names, images or URLs, device identifiers (including advertising IDs), or location data. This collection is a condition of using the app under these Terms; it begins when you accept them on the screen shown at first launch, and nothing is sent before that. The data is used only for statistical analysis toward the purposes above and is never provided to third parties.

9. Changes to these Terms

If we change these Terms, we will announce it on this page. Significant changes will also be notified within the app. Continued use after a change constitutes acceptance.