Privacy Policy
Last Updated: July 16, 2026
This Privacy Policy describes how Miyabi J-Prep (the "Application"), a TOEIC-Style Japanese Practice Platform, handles user information.
1. Account Types and Data Collection Choices
Miyabi J-Prep offers three modes of operation, allowing you to choose how your data is managed:
- Guest Mode (Anonymous Use): You can use the app without creating an account. In Guest Mode, we do not collect personal information (like your name or email) or sync your data to our servers. All of your Japanese language learning statistics, progress, and settings are stored strictly locally on your device. We display advertisements via Google AdMob in this mode. If you delete the app or clear your device cache, your local learning data will be permanently lost.
- Sign-In Mode (Free Registered Account): If you choose to sign in using Google Sign-In, we collect basic profile data to create your account. This mode backs up your learning statistics to our cloud servers so you don't lose your progress. We display advertisements via Google AdMob in this mode.
- Premium Mode (Paid Subscription): If you purchase a premium subscription, your subscription status is securely managed via RevenueCat. You will enjoy an entirely ad-free experience (no AdMob tracking or ads). Your learning statistics are continuously securely synced to the cloud.
2. Information We Collect and How We Use It
Depending on your chosen mode, the Application may collect or interact with the following data types:
A. Personal Information (Sign-In & Premium Modes Only)
- Authentication Data: When logging in via Google Sign-In (OAuth 2.0), we receive your name, email address, and a unique user identifier provided by Google. This is used solely for Account Management.
- Learning Statistics: In Premium modes, your learning data (count of total answered questions, correct questions, daily streak, and JLPT level performance breakdown) is securely uploaded to our cloud servers to synchronize your progress across sessions.
B. Financial & Purchase Data (Premium Mode Only)
When you buy a subscription, transaction status and validation tokens are processed securely in conjunction with RevenueCat. We do not collect or store your actual credit card details or payment methods; all billing is handled entirely by the Google Play Billing system.
C. Device and Network Identifiers (Guest & Sign-In Modes Only)
To support our free tiers, we integrate with Google AdMob. AdMob may collect and process device advertising identifiers (such as the Android Advertising ID - AAID) and basic device telemetry data to serve, personalize, and measure contextual or targeted advertisements.
3. Information We Collect and How We Use It
For Guest Users (Local Storage)
Guest data is stored directly on your device using the browser's standard Local Storage (localStorage). You can delete all your stored history and settings at any time by clicking "Reset All Stats" in the Settings screen of the application. The data will be permanently deleted and can no longer be restored.
Account Deletion and Data Retention (Sign-In & Premium Users)
You have the right to request the deletion of your cloud account and all associated personal data at any time.
- How to request deletion: You can submit a deletion request through our web request form here: https://docs.google.com/forms/d/e/1FAIpQLScVTmhgGJRtRbsYufCkt_HWpRTOisd4LEXTFZB1Myh0oMcqsg/viewform?usp=dialog
- HWhat is erased: Upon receiving your request, we will permanently delete your profile name, email address, associated user tokens inside RevenueCat, and your entire Japanese learning statistics history.
- Processing Time: We will fulfill manual data deletion requests and permanently erase your information from our active databases within 30 days of submission. A confirmation email will be sent to your registered address once completed.
4. Use of Device Features
The application integrates with certain device components to provide features:
Text-To-Speech (TTS)
- Feature: Used to read listening passages, dialogues, and questions out loud in Japanese.
- Integration: The app utilizes the native Text-to-Speech API of your device (via the Capacitor Community Text-to-Speech plugin for mobile or the standard Web Speech API for browsers).
- Data Handling: No text content, audio files, or transcripts are sent to the developer. The TTS conversion happens strictly locally on your device. Please note that your device's operating system provider (such as Apple or Google) handles the TTS generation according to their own system privacy settings and terms of service.
5. Third-Party Web Assets
To deliver the application's unique visual style, we load static font resources from Google Fonts (`fonts.googleapis.com`). No tracking cookies are used to query these assets, and they are fetched directly to render typography on your device.
6. Age Restriction & Children's Privacy
The Application is intended strictly for an adult audience (individuals aged 18 and older) and is not designed for, marketed to, or intended for use by children. We do not knowingly target, solicit, or collect information from children under the age of 18. If you are under 18 years of age, you are not permitted to use this Application.
7. Changes to This Privacy Policy
We may update our Privacy Policy from time to time. Any changes will be reflected by updating the "Last Updated" date at the top of this document. Since data is not sent to any servers, we cannot notify users individually of updates, and we encourage you to review this policy periodically.
8. Contact Us
If you have any questions or feedback about this Privacy Policy, please contact us at: