Privacy Policy

Japanese learning app “Japanese Master”

Artwoo Co., Ltd. (株式会社アートウー) (the “Operator”) sets out below how user information is handled in the smartphone app “Japanese Master” (iPhone and Android versions) (the “App”).

1. Information we collect

The App does not collect information that can identify you. There is no account registration, and the App does not ask for your name, email address, location, or contacts. The App contains no advertising or usage-analytics tools. For how information is handled when you buy the paid “Premium”, see “6. Premium purchases”.

2. Information stored only on your device

The following information is stored only on your device and is not sent anywhere, including to the Operator.

Learning records (words learned, review schedule, study streak, achievements, favorites, etc.)
Settings (display language, furigana and romaji display, reminder time, etc.)
Downloaded word audio files

Deleting the App also deletes this information. However, if you use your device’s backup (iCloud or Google), your learning records and settings may be included in that backup (stored with your Apple ID or Google account). The Operator does not receive this content.

3. Microphone

The App uses the microphone in pronunciation practice to record your voice so you can play it back and compare it with the model audio. Recordings are played back only on your device; they are not sent anywhere and are not saved outside the App. You can revoke microphone permission anytime in your device settings.

4. Notifications

Study reminders are notifications scheduled on your device. No information is sent anywhere for notifications.

5. Audio downloads and app updates

Word audio is downloaded as needed from Google Cloud Storage (a service of Google LLC). Due to how network communication works, connection information such as your IP address may be recorded on Google’s servers. This information is handled under Google’s privacy policy, and the Operator does not use it to identify you.

In addition, so that bugs and content errors can be fixed without going through the stores, the App checks with EAS Update (a service of 650 Industries, Inc. (Expo)) for new updates when it starts, and downloads any it finds. At that time, connection information such as your IP address, OS type, the App version and update identifier, and a random ID the App creates for each device are sent. If a serious error caused by an update occurred the last time the App was opened, details of that error are also sent. This information is sent only to deliver updates, is not linked to your name or email address, and is not used by the Operator to identify you. Expo handles it under Expo’s privacy policy.

6. Premium purchases

Premium purchases and checks on whether you have purchased use RevenueCat (a service of RevenueCat, Inc.). The following information is therefore sent to RevenueCat.

An anonymous ID the App creates for each device (not linked to your name or email address)
Purchase history (plan purchased, purchase date, expiration date, App Store / Google Play purchase information)
Connection information such as device model, OS version, country or region, and language

This information is used only to process purchases, restore purchases, and check whether Premium is active. It is not used for advertising or to track you. Payment information (such as credit card numbers) is handled by Apple or Google; neither the Operator nor RevenueCat receives it. RevenueCat handles information under RevenueCat’s privacy policy.

7. Backups

When you create a backup, the App puts your learning records into a single file and saves it to the location you choose (such as iCloud Drive, Google Drive, or the Files app on your device). You choose where it is saved, and the Operator does not receive its content.

8. Use by children

The App does not collect personal information, so it can be used safely at any age. Minors should get a parent’s or guardian’s consent before buying Premium.

9. Information sent to third parties

The App sends information to the following third parties. The information sent is handled under each party’s privacy policy.

RevenueCat (managing Premium purchases)

Recipient: RevenueCat, Inc.

Information sent: An anonymous ID the App creates for each device; purchase history (plan purchased, purchase date, expiration date, App Store / Google Play purchase information); and connection information such as device model, OS version, country or region, and language

Purpose: Processing purchases, restoring purchases, and checking whether Premium is active

App Store and Google Play payments

Recipient: Apple Inc. / Google LLC

Information sent: The plan purchased and purchase information

Purpose: Payment for Premium and checking eligibility for the free trial

EAS Update (delivering app updates)

Recipient: 650 Industries, Inc. (Expo)

Information sent: A random ID the App creates for each device; connection information such as IP address; OS type; the App version and update identifier; and details of serious errors caused by an update (when they occur)

Purpose: Checking for and downloading app updates

Google Cloud Storage (delivering word audio)

Recipient: Google LLC

Information sent: Connection information such as IP address, and the audio files downloaded

Purpose: Downloading word audio

10. Changes to this policy

The Operator may revise this policy as the App’s features change. Important changes will be announced on this page.

11. Contact

Artwoo Co., Ltd. (株式会社アートウー)
Email: support@artwoo.co.jp

Effective date: October 27, 2026 · Last updated: November 9, 2026