Kotoba QuestLearn Japanese

Privacy Policy

Established October 25, 2026

1. Introduction

Kotoba Quest (the "app") is a Japanese learning app offered by 株式会社メディアリープ ("we", "us"). This Privacy Policy (this "Policy") explains the information the app handles, the purposes of use, and how we manage it.

You can use the app without creating an account (anonymous use is the default). Your learning record is stored on your device first; it is backed up to the cloud only if you sign in. AI features run only when you operate them, and we do not store recordings or questions. The app shows no ads and we never share or sell data for advertising. Please read this Policy before using the app.

2. Information about the operator

Operator
株式会社メディアリープ
Representative
笹尾 祐太朗(代表取締役)
Address
Nerima 1-20-8, Nikkei Nerima Bldg. 2F, Nerima-ku, Tokyo 176-0001, Japan
Email
info@media-leap.com
Corporate website
https://media-leap.com/

3. Information we handle and purposes of use

The information the app handles is as follows. Information marked "device only" is stored only on your device and is not sent to our servers.

Learning record (progress, notes, review schedule, diary, settings)
Stored on your device to run the app’s learning features. If you signed in with learning backup on, the same content is backed up to our cloud (Firebase) (see "4. Accounts and learning-data backup").
Account information
When you start anonymously, only an anonymous user ID we issue (the Firebase uid) is used. If you optionally sign in with Apple or Google, we receive identifiers from that account such as your name and email address. Used to manage learning backup and confirm Kotoba Pro entitlement.
Audio and phrase for AI pronunciation feedback
Only when you ask for feedback, your recording (up to 12 seconds) and the phrase are sent to our server and to Google’s Gemini service (Google Cloud / Vertex AI) (see "5. External transmission and processing for AI features"). We do not store recordings.
Questions to the AI tutor
Only when you ask, your question, the phrase you are studying, and practice words (up to 20) are sent the same way. We do not store questions or replies.
AI answer reports
When you report a problem with an AI answer, only the reason you picked, the AI text shown, the screen, and the date are sent (see "6. Reporting AI answers").
Usage counts (off by default)
Only if you turn on "Share usage counts" in Settings, daily counts of a fixed list of actions (e.g. "opened Pro screen", "finished AI check") and, once a week, rough ranges of study days, scenes, reviews, listening minutes and recordings are sent (see "9. Usage counts"). Answers, phrases, questions, recordings and contact details are never sent.
Crash reports
In release builds, crash details, device model, OS version and similar diagnostics are sent to Firebase Crashlytics (see "10. Crash reports"). No user ID, answers, phrases or recordings are included.
Notification token
Only when notifications are permitted and you are signed in, the Firebase Cloud Messaging token is registered with our server for delivering notifications (see "7. Notifications").
Kotoba Pro entitlement status
If you subscribe, only whether Pro is active, when it ends, whether it is a trial, and whether it will renew is stored on our server (see "8. Kotoba Pro purchases"). We do not store prices, receipts, country or payment details.

4. Accounts and learning-data backup

You can use the app anonymously. Sign-in with Apple or Google is only needed to turn on learning backup. Signing in or not does not change what you can learn: every course scene and every review is free to complete.

When you sign in, your learning record is backed up to our cloud (Firebase) so you can continue on another device. Communication between the app and our servers is encrypted, and every request carries your own authentication token and an App Check token.

You can delete your backed-up learning data and account at any time from "Delete account" in the app. If you subscribe to Kotoba Pro, cancel the subscription itself in your App Store or Google Play account settings.

5. External transmission and processing for AI features

For AI pronunciation feedback, your recording (up to 12 seconds) and the phrase are sent through our server to Google’s Gemini service (Google Cloud / Vertex AI) to produce feedback. For the AI tutor, your question, the phrase you are studying, and practice words (up to 20) are sent the same way.

We do not store recordings, questions, or AI replies. Our logs hold only counts such as how long a request took. Google processes this content under the Google Cloud terms (https://cloud.google.com/terms/) and may keep it briefly to detect abuse.

AI answers are generated by a general model and can be wrong. AI results never change your progress or scores in the app. AI features have fair-use limits shown in the app (including the free sample).

6. Reporting AI answers

When you report an AI answer, only the reason you picked, the AI text you saw, the screen it was on, and the date are sent to us. No account ID, no recording, no exact time. Reports queue on the device while offline and are sent when connectivity returns.

7. Notifications

Study reminders and other notifications work only if notifications are permitted on your device and you are signed in. In that case the Firebase Cloud Messaging token is registered with our server. The token is used only to deliver notifications and is removed before you sign out.

8. Kotoba Pro purchases

App Store or Google Play processes the payment for Kotoba Pro; we never receive your card or bank details. We use RevenueCat, Inc. to confirm purchases with the store. RevenueCat receives the store’s purchase record and the anonymous user ID the app uses for learning data, and tells our server only whether Pro is active, when it ends, whether it is a trial, and whether it will renew.

We do not store prices, receipts, country or payment details. When you delete your account in the app, the stored status is deleted with it. Cancel the subscription itself in your App Store or Google Play account settings.

9. Usage counts

"Share usage counts" in Settings is off by default. If you turn it on, the app sends daily counts of a fixed list of actions (e.g. "Kotoba Pro screen opened", "plan chosen", "AI check finished"), and once a week rough ranges of how many days you studied and how many scenes, reviews, listening minutes and recordings you did.

Counts are added together on our server per day and are not stored with your account ID, device ID or exact time. We never send your answers, phrases, questions, recordings or contact details, and we use no advertising identifiers and no third-party analytics. To stop abusive traffic we keep a per-account daily total, deleted with your account. Turning the setting off deletes counts not yet sent.

10. Crash reports

Release builds collect crash reports through Firebase Crashlytics: the crash itself, device model, OS version and similar diagnostic data, with no user ID, no answers, no phrases and no recordings. Debug builds collect nothing. Crash collection is separate from the "Share usage counts" switch.

11. Advertising

The app shows no ads. We do not share or sell data for advertising.

12. Outsourcing and external services

We use the following external services only as needed to provide the app’s features, after confirming appropriate protective measures.

  • Learning-data backup and authentication: Google LLC (Firebase)
  • AI processing: Google LLC (Google Cloud / Vertex AI / Gemini)
  • Subscription verification: RevenueCat, Inc.
  • App API and notification delivery: Microsoft Corporation (Azure)
  • Crash reports: Google LLC (Firebase Crashlytics)

13. Cross-border transfer of personal information

The external services above operate servers outside Japan, such as in the United States. User IDs, learning-data backups and content sent to AI features may therefore be transferred outside Japan. In line with the Act on the Protection of Personal Information, we take the measures required by law, such as concluding standard contractual clauses, when using these providers.

14. Provision to third parties

We will not provide personal information to third parties without the consent of the data subject, except as permitted by law, such as in the following cases.

  • When required by laws and regulations
  • When necessary to protect the life, body or property of a person and it is difficult to obtain the data subject’s consent
  • When particularly necessary to improve public health or promote the sound growth of children and it is difficult to obtain the data subject’s consent
  • When cooperating with a national institution, a local government, or a party entrusted by them in performing affairs prescribed by laws, and obtaining the data subject’s consent may hinder those affairs

15. Retention and deletion

Recordings, questions and AI replies sent for AI features are handled only transiently for processing and are not stored by us. Learning-data backups and account information are retained until the account is deleted. Usage counts are retained as daily totals and deleted with the account. Crash reports are retained for the period needed for improvements.

You can delete your account at any time from "Delete account" in the app. Device-only data is removed from the device when you uninstall the app.

16. Requests for disclosure, correction, suspension, etc.

For opinions or complaints about this Policy, or requests regarding information related to your account, please email info@media-leap.com. After confirming your identity (or your agent’s), we will respond free of charge, usually within 30 days, or explain why we cannot. Learning data can be reviewed and deleted by you in the app at any time.

17. Minors

The app is not a children’s-category app, but it is intended for a wide range of ages. Users under 18 should sign in, subscribe, or use AI features only with a parent or guardian’s consent.

18. Security

To prevent leakage, loss or damage to the information we handle, we take security measures such as encrypted communication (TLS), request verification with App Check, and access control. In the unlikely event of an incident, we will promptly take the necessary measures and explain within the necessary scope.

19. Links to other websites and apps

Handling of information on external websites and apps linked from the app or this page (including the stores) follows their own privacy policies; we are not responsible for them.

20. Changes to this Policy

We may change this Policy as features or laws change. The revised Policy takes effect when posted on this page. Significant changes may be announced in the app.