Privacy Policy

1. Information We Collect

When you create an account, we collect your email address and a securely hashed version of your password. We do not store your password in plain text.

As you use the app, we store your study progress (vocabulary and kanji status), display preferences (e.g., show/hide meanings), and session data for authentication.

2. How We Use Your Information

• To provide and maintain the study service
• To authenticate your account and manage sessions
• To save and restore your study progress across devices
• To send password reset emails and two-factor authentication codes when requested
• To process subscription payments through Stripe

3. Data Storage

Your data is stored on our server located in Tokyo, Japan. Data is not replicated to other regions. Backups are maintained for disaster recovery purposes only.

4. Third-Party Services

We use the following third-party services:

• Stripe — for payment processing. When you subscribe, your email and payment information are shared with Stripe. See Stripe's Privacy Policy.
• Purelymail — for transactional emails (password resets, 2FA codes). Your email address is transmitted through this service.

We do not sell, rent, or share your personal information with any other third parties.

5. Cookies

We use a single session cookie to keep you logged in. This cookie is essential for the service to function and contains only a random session identifier. We do not use tracking cookies or analytics.

6. Data Retention

Your account data and study progress are retained for as long as your account is active. If you wish to delete your account and all associated data, please contact us at the email below.

7. Security

Passwords are hashed using industry-standard algorithms. Sensitive settings (SMTP credentials, API keys) are encrypted at rest using AES-256. Two-factor authentication is available for additional account security.

8. Your Rights

You have the right to:

• Access the personal data we hold about you
• Request correction of inaccurate data
• Request deletion of your account and data
• Export your study progress data

9. Children

This service is not intended for children under the age of 13. We do not knowingly collect personal information from children under 13.

10. Changes

We may update this privacy policy from time to time. Changes will be posted on this page with an updated revision date.

11. Contact

For privacy-related inquiries, contact us at [email protected].