Dedicated Japanese Reader App

Terms of Use

Last updated: May 19, 2026

1. The Service

Kotogoo - Japanese Reading helps users read Japanese stories and study Japanese sentences with AI-generated translations, vocabulary explanations, grammar explanations, saved vocabulary/grammar cards, flashcard review, and Japanese text-to-speech narration. The app may include bundled stories, stories loaded from the Reader Firebase project, free AI usage, and paid Reader Premium features.

2. Eligibility

• You must be at least 13 years old to use the app.
• If you are under the age of majority in your country, you must have permission from a parent or legal guardian.
• You are responsible for keeping your account credentials secure.
• You must provide accurate information when creating or maintaining an account.

3. Accounts and Email Verification

You may use parts of the Reader app as a guest, subject to guest usage limits. Some account, subscription, restore, and signed-in usage features require a verified account. You may sign in with email/password or Sign in with Apple where available. We may send account verification emails and may restrict premium purchases, restore actions, or signed-in backend requests until your email address is verified. You are responsible for all activity under your account.

4. Acceptable Use

You agree not to:

• Use the app for unlawful, harmful, abusive, or deceptive activity.
• Attempt to bypass usage limits, authentication, subscription checks, or security protections.
• Reverse engineer, scrape, copy, resell, publicly repost, or redistribute the app, story library, generated audio, or service content except as permitted by law.
• Use automated systems to overload, spam, or abuse the service.
• Submit content that infringes the rights of others or violates applicable law.

5. AI-Generated Content

The app uses AI systems to generate translations, vocabulary lists, grammar notes, and narration. AI-generated content may be inaccurate, incomplete, or inappropriate for your specific learning context. You should treat AI output as study assistance, not as professional translation, legal advice, medical advice, or any other professional advice.

You retain rights to text you submit, but you grant us the limited right to process it to provide, secure, cache, and improve the app. We may use automated systems and third-party AI or cloud providers to process requests. You are responsible for deciding whether AI output is suitable for your study use.

6. Free Usage and Limits

Free usage may be limited by daily AI usage counters, guest limits, feature restrictions, or account status. Reading the included story content may remain available even when AI generation or narration limits are reached. We may adjust limits, models, narration voices, or available features to manage reliability, cost, abuse prevention, and service quality.

7. Local Study Data

Continue-reading progress, saved vocabulary, saved grammar, and flashcard review history may be stored locally on your device unless the app specifically provides cloud sync for that data. Local study data may be lost if you delete the app, clear app data, reset your device, or use a different device without a supported sync feature.

8. Reader Premium Subscription

• Payment is charged to your Apple ID at confirmation of purchase.
• The subscription automatically renews unless canceled at least 24 hours before the end of the current period.
• Your Apple ID account is charged for renewal within 24 hours before the end of the current period.
• You can manage or cancel your subscription in Apple ID subscription settings.
• Refund requests are handled by Apple under Apple's refund policies. We do not directly process App Store refunds.
• If payment cannot be completed, or if Apple reports that a subscription is expired, revoked, refunded, or otherwise invalid, premium access may be suspended or removed.

9. Apple Terms

For iOS users, your use of the app is also subject to Apple's App Store terms, payment rules, and the Apple Standard End User License Agreement to the extent applicable. These Terms govern the service we operate; Apple is not responsible for the app's AI outputs, support, subscriptions, or service content except as required by Apple's own terms. Apple and Apple's subsidiaries are third-party beneficiaries of these Terms for App Store-distributed versions of the app.

10. Intellectual Property

The app, brand, interface, software, curated story content, images, generated narration service, and service design are owned by us or our licensors. You may use the app only for personal language learning unless we give written permission for another use. You may not redistribute the story library, generated audio, or premium features as a competing dataset, service, or product.

11. Privacy

Your use of the app is also governed by our Privacy Policy, which explains how we collect, use, and protect information.

12. Account Deletion and Termination

You may request Reader account deletion through the app where available or by contacting support. We may suspend or terminate access if you violate these Terms, create risk for the service, abuse AI features, attempt to bypass usage or subscription checks, or use the app unlawfully. Deleting an account does not automatically cancel an App Store subscription; subscriptions must be managed through Apple ID subscription settings.

13. Disclaimers

The app is provided "as is" and "as available." We do not guarantee uninterrupted service, error-free operation, availability of a particular AI model, availability of a specific narration voice, preservation of local study data, or perfect accuracy of translations, explanations, vocabulary, grammar analysis, or narration.

14. Limitation of Liability

To the maximum extent permitted by law, we are not liable for indirect, incidental, special, consequential, or punitive damages, lost profits, lost data, learning outcomes, or reliance on AI-generated content. Some jurisdictions do not allow certain limitations, so some limits may not apply to you.

15. Changes to the Service or Terms

We may update the app, add or remove stories, change features, adjust usage limits, change AI models or narration providers, update subscription benefits, or revise these Terms. If changes are material, we will provide notice where appropriate. Continued use after changes means you accept the updated Terms.

16. Governing Law

These Terms are governed by the laws of Japan, without regard to conflict-of-law rules, unless mandatory consumer protection laws in your location provide otherwise.

17. Contact