TENSU Privacy Policy

Last updated: October 22, 2026

ZUKAI Inc. ("we", "us", "our") sets forth the following terms regarding the handling of user information in the iOS application "TENSU" (the "App").

1. Information We Collect

The App does not require user registration. We handle the following information.

1-1. Data Stored on Your Device

• Score (0–100, in 5-point increments)
• Reasons (the App's common reasons or reasons you created)
• Diary (optional)
• Date and time of recording
• Birth year (used only on device for calculating age group)
• App settings (week start day, consent status, etc.)

These data are stored on your device in JSON format. Your diary, reasons you created, and your birth year are never sent. The parts used for the "People" tab, such as scores, are sent as described in 1-2. If iCloud Backup is enabled on your device, these data are included in iCloud Backup, which is managed by Apple's services and your device settings.

1-2. Data Sent to Our Servers

To show score distributions in the "People" tab, when you save or edit a score, the App sends the following data about that day's record to Firebase Firestore (Tokyo region), provided by Google LLC:

• Score (0–100, in 5-point increments)
• Region code (ISO 3166-2 prefecture code such as "JP-13", or country code such as "US")
• Age group (10-year age range calculated from birth year, e.g., "20s", "30s")
• Record date (the day you scored, e.g., 2026-10-20)
• Reason types (only when you attach one of the App's common reasons to that day's record; a fixed code identifying which reason is sent)
• Creation time (the time the server received the record)

The App does not send:

• Your name, email address, a user ID, or any ID that identifies your device
• Your birth year (it is converted to an age group before sending)
• Your diary
• Reasons you created
• Location data itself (see 1-3)

Each record's ID changes every day. Each record is stored under an ID computed from the record date and a secret value that is kept only on your device. Records for the same day get the same ID, so editing overwrites the earlier one (one record per day). The ID changes from day to day, and the secret value never leaves your device, so the IDs cannot be used to link records from different days to the same device.

Submitted data is stored so that users of the App can read it, in order to compute the "People" tab. Versions 1.1.0 and earlier of the App also sent the names of reasons you created.

Versions 1.0.2 and earlier of the App included a fixed per-device ID in each record's ID. On October 22, 2026, we replaced the IDs of those records with values that cannot link records from the same device (the scores and other contents were not changed). Since then, records sent from versions 1.0.2 and earlier are not accepted.

1-3. Use of Location Information

On first launch, the App may request permission to use approximate location to determine your region (prefecture).

• Location data is collected at coarse precision (prefecture level) only
• After determining your region, the location data itself is immediately discarded
• Only the region name (e.g., "Tokyo") is stored in the device's Keychain
• Only the region code is sent to the server (see 1-2)
• If you do not grant location permission, you can manually select your region from the Settings screen
• Your region setting can be changed or cleared at any time from the Settings screen

2. Purpose of Use

• Providing score recording, viewing, and analysis features
• Displaying the "People" tab (anonymous statistics screen)
• Analyzing usage to improve and maintain App quality

3. Analytics Tools

The App uses Firebase Analytics (Google Analytics for Firebase), provided by Google LLC, for feature improvement and quality maintenance. Collection starts when the App launches.

The following information is collected:

• Screen views (which screens you open)
• Operation events (saving a record, switching tabs, opening Settings, etc.; saved scores are sent only as a range such as "0–19")
• Views of the in-app purchase screen and the result of a purchase or restore (completed, cancelled, type of failure, etc.). Payments are processed by Apple; we do not receive card numbers or other payment information
• Usage such as app launches and time spent in the App
• Device type, OS version, language settings, and App version
• An identifier Firebase assigns to each installation of the App (app instance ID)
• Approximate location (country and region) inferred from your IP address

The advertising identifier (IDFA) is not collected. We do not collect your name or email address, and this data is not linked to the records sent for the "People" tab (1-2). We do not use it for advertising or sell it to third parties.

The App currently has no setting to turn off Firebase Analytics collection.

Collected data is handled in accordance with Google's Privacy Policy: https://policies.google.com/privacy

3-1. Remote Configuration

We use Firebase Remote Config, provided by Google LLC, to allow remote adjustment of in-app display thresholds (such as community screen aggregation thresholds).

Information collected is limited to device identifiers (instance IDs) and connection environment. No personally identifiable information or recorded data is transmitted. Configuration values are managed on the server side and applied when the App launches.

3-2. Crash Reports

We use Firebase Crashlytics, provided by Google LLC, to improve the stability of the App.

The following information is collected:

• Stack traces at the time of a crash
• Device type, OS version, and App version
• Operation logs before and after a crash (within a non-personally-identifiable scope)
• Records of errors inside the App (for example, when sending data fails)

We do not collect personally identifiable information such as name, email address, or user_id. Crash report collection begins when you agree to the Terms of Use and Privacy Policy. No data is collected before consent.

4. Provision to Third Parties

Except as required by law, we do not provide user information to third parties.

5. Data Storage and Deletion

Data stored on your device is erased when the App is uninstalled, and you can also delete individual records. Because we cannot tell which records sent to the server (1-2) belong to whom, we cannot respond to individual deletion requests. Deleting a record on your device does not remove a record that has already been sent.

Data included in OS-level backups (such as iCloud Backup) is managed according to your device settings and the OS provider's specifications.

6. Revisions

This Policy may be revised as necessary. Revised content takes effect when posted on this page. If a revision has significant impact on users, we will notify you via the App or our website.

7. Contact

For inquiries regarding this Policy, please contact support@zukai.co. For information about our company, please visit https://zukai.co.