Amestella Privacy Policy

Effective Date: March 31, 2026
Last Updated: July 7, 2026


Grosbeak Inc. ("we," "us," or "our") operates the Amestella fortune-telling entertainment application ("the App"). This Privacy Policy explains how we collect, use, disclose, and safeguard your personal information when you use the App. Please read this policy carefully. By using the App, you consent to the practices described herein.

In this Privacy Policy, "personal information" means "personal information" as defined in Japan's Act on the Protection of Personal Information (information about a living individual that can identify a specific individual by name, date of birth, or other description, or that contains an individual identification code), as well as other information about an individual — such as an email address — that is used in connection with a specific individual.

1. Company Information

ItemDetails
Company NameGrosbeak Inc. (Grosbeak Kabushiki Kaisha)
RepresentativeTomonori Hamada
Address8-2-6 Okidome, Ikaruga-cho, Ikoma-gun, Nara 636-0123, Japan
ContactInquiry Form

2. Information We Collect

2.1 Account Information

Data ItemRequired/OptionalPurpose
Email addressRequiredAccount authentication, important notifications
Display nameRequiredIn-app user display
Profile photoOptionalIn-app user display
Phone numberOptionalAccount authentication (phone sign-in)

2.2 Fortune Calculation Data

Data ItemRequired/OptionalPurpose
Date of birthRequiredFortune calculations across multiple divination systems
Time of birthOptionalPrecise astrological calculations
Place of birthOptionalAstrological house calculations
Latitude/LongitudeOptionalCelestial position calculations (auto-derived from birthplace)
GenderOptionalUsed in certain divination systems

2.3 Pet Information

Data ItemRequired/OptionalPurpose
Pet nameRequiredPet fortune features
Pet typeRequiredPet fortune features
BreedOptionalPet fortune features
Pet date of birthRequiredPet fortune calculations
Pet genderOptionalPet fortune features
Pet photoOptionalIn-app pet display
Pet birthplaceOptionalPet fortune calculations

2.4 Usage Information

Data ItemPurpose
Subscription statusBilling management, service delivery
Pentacle balanceIn-app currency management
Transaction historyPurchase and usage record keeping
Fortune resultsSaving and displaying fortune history
Compatibility historySaving and displaying compatibility results
FCM tokenPush notification delivery

2.5 Device and Diagnostic Information

Data ItemPurpose
Device model, OS version, app versionBug analysis, quality improvement, and customer support
Crash information (stack traces, etc.)Detecting and fixing app defects (Firebase Crashlytics)
Performance information (startup time, network conditions, etc.)Improving app quality and performance (Firebase Performance Monitoring)
Usage data (screen views, interaction events)Analysis for service improvement (Firebase Analytics; collected with the user's consent)

When you send an inquiry or feedback, your user ID, app version, OS version, and device model are passed to the inquiry form (Google Forms) — only to the extent you select with the checkboxes — so we can review your situation.

3. How We Use Your Information

We use the information we collect for the following purposes:

  1. Performing fortune calculations and compatibility readings using various divination systems
  2. Generating AI-powered fortune interpretations via Google Gemini AI
  3. User account authentication and management
  4. Subscription and in-app purchase management
  5. Sending push notifications (fortune results, compatibility results, announcements)
  6. Improving the App and developing new features
  7. Responding to user inquiries
  8. Enforcing our Terms of Service
  9. Complying with legal obligations

4. Information Shared with Third Parties and Entrustment

Except as required by law or with your consent, we do not provide your personal information to third parties. However, to the extent necessary to provide the App's services, we entrust the handling of personal information to the following external service providers. Under Japan's Act on the Protection of Personal Information, this constitutes "entrustment," and these providers process personal information only within the scope of the entrusted purpose and in accordance with our instructions and agreements. We exercise necessary and appropriate supervision over these providers.

4.1 Firebase (Google LLC)

ServiceData SharedPurpose
Firebase AuthenticationEmail, display name, profile photoUser authentication
Cloud FirestoreUser data, fortune results, pet dataData storage and management
Firebase Cloud StorageProfile photos, pet photosImage file storage
Firebase Cloud MessagingFCM tokenPush notification delivery
Firebase App CheckDevice informationFraud prevention
Firebase Cloud FunctionsFortune calculation dataServer-side processing
Firebase CrashlyticsCrash information and device info (model / OS version / app version)Detecting and fixing app defects
Firebase Performance MonitoringPerformance information and device infoImproving app quality and performance
Firebase AnalyticsUsage data (screen views, events); collected with the user's consentAnalysis for service improvement

Google Privacy Policy: https://policies.google.com/privacy

4.2 Google Gemini AI API (Google LLC)

Data SharedPurpose
Date of birth, time of birth, gender (anonymized)AI-generated fortune interpretations
Pet information (type, breed, date of birth)AI-generated pet fortune interpretations

Data is sent to Google Gemini AI API through Cloud Functions (server-side) only. Your name, email address, and other directly identifying information are not transmitted to the AI service.

Google AI Privacy Notice: https://ai.google.dev/terms

4.3 RevenueCat, Inc.

Data SharedPurpose
User ID (anonymous identifier)Subscription and purchase management
Purchase information (Apple receipt, Google purchase token, last seen time, device type and OS)Purchase verification and management

RevenueCat, Inc. is located in the United States, and the data shared is stored and processed in the United States (e.g., on Amazon Web Services). RevenueCat acts as our service provider (data processor), processing the data only on our documented instructions, and does not sell or share it (it qualifies as a "Service Provider" under the California Consumer Privacy Act (CCPA)). To provide its services, RevenueCat may use sub-processors located in the United States (including Amazon Web Services, Snowflake, Google LLC, OpenAI, and Anthropic). We do not transmit sensitive information such as your date of birth, place of birth, location data, or fortune-telling results to RevenueCat.

4.4 Google Maps Platform (Google LLC)

Data SharedPurpose
Place of birth (location name)Geocoding (converting place names to coordinates)

4.5 Authentication Providers

ProviderData SharedPurpose
Google Sign-In (Google LLC)Authentication tokensAccount authentication
Sign in with Apple (Apple Inc.)Authentication tokensAccount authentication

4.6 Inquiry Form (Google Forms / Google LLC)

Data SharedPurpose
User ID, app version, OS version, device model (to the extent you select)Responding to inquiries and feedback; reviewing your situation

Our inquiry form and feedback box are provided via Google Forms, and submissions are processed on Google LLC's servers (United States). You can choose which information to include using checkboxes and review it before sending.

4.7 No Sale of Personal Information

We do not sell, rent, or trade your personal information to third parties for their marketing purposes. Under the California Consumer Privacy Act (CCPA), we confirm that we have not sold personal information of consumers in the preceding 12 months.

5. Data Storage and Retention

5.1 Storage Location

Your personal information is stored on Google Cloud Platform (Firebase) servers, primarily in the Tokyo region (asia-northeast1), Japan.

5.2 Retention Period

Data TypeRetention Period
Account informationUntil account deletion
Fortune results and compatibility historyUntil account deletion
Pet informationUntil account deletion
Transaction historyUntil account deletion, or as required by law (up to 5 years)
Push notification tokensUntil account deletion

5.3 International Data Transfers

Some of the third-party service providers we use are located outside Japan. In particular, subscription and purchase data shared with RevenueCat, Inc., as well as data handled by Google LLC and Apple Inc., is transferred to and processed in the United States. If you are located outside Japan, your information may also be transferred to and processed in Japan. By using the App, you consent to these international transfers. We ensure that appropriate safeguards (such as Standard Contractual Clauses and Data Processing Addenda) are in place to protect your data in compliance with applicable data protection laws.

6. Your Rights

6.1 Rights Under Japanese Law (Act on the Protection of Personal Information)

If you are located in Japan, you have the right to:

6.2 Rights Under the General Data Protection Regulation (GDPR)

If you are located in the European Economic Area (EEA), you have the following additional rights:

To exercise these rights, please contact us through our inquiry form.

6.3 Rights Under the California Consumer Privacy Act (CCPA)

If you are a California resident, you have the following rights:

To submit a CCPA request, please contact us through our inquiry form.

7. Account Deletion and Data Removal

  1. You may request account deletion through the Settings screen within the App.
  2. Upon account deletion, we will delete all of the following data:
    • Account information (email, display name, profile photo)
    • User profile (date of birth, time of birth, place of birth, gender, etc.)
    • Fortune results and compatibility history
    • Pet information and pet fortune results
    • Pentacle balance and transaction history
    • Profile photos and pet photos (storage)
    • Push notification settings and tokens
    • Public ID information
  3. When you request account deletion, the account is deactivated immediately and the data above is permanently deleted after a 30-day grace period. You can cancel the deletion and restore the account by signing in again during the grace period (a safeguard against accidental deletion and abuse).
  4. Data required to be retained by law will be kept for the legally mandated period and deleted thereafter.
  5. Minimal data retained for fraud prevention: To pursue our legitimate interest in preventing fraudulent acquisition of rewards (such as repeatedly deleting and re-registering accounts to obtain referral bonuses multiple times), we may retain, even after account deletion, an irreversible hash value derived from your email address or social login identifier together with a record of whether rewards were received. This information is not used for any purpose other than fraud prevention.
  6. After permanent deletion, deleted data cannot be recovered.

8. Cookies and Tracking Technologies

8.1 Mobile Apps

The iOS and Android versions of the App do not use cookies. However, Firebase SDK may use device identifiers for functionality purposes.

8.2 Analytics

The App uses Firebase Analytics (Google Analytics for Firebase) to collect and analyze usage data such as screen views and interaction events. This information is collected based on the user's consent and is used solely to improve the App. You may change (turn off) your consent to usage analytics at any time from the "User Settings" screen within the App. For details on the information collected, please also refer to "2.5 Device and Diagnostic Information" and "4.1 Firebase" above.

9. Children's Privacy

  1. The minimum age to use the App is 16. The App is not intended for use by children under the age of 16.
  2. If a user under the age of 18 (a minor) wishes to make paid purchases (subscriptions, Pentacles, etc.), the consent of a parent or legal guardian is required.
  3. We do not knowingly collect personal information from children under 16. If we become aware that we have collected personal information from a child under 16, we will promptly delete such data.

10. Data Security

We implement the following security measures to protect your personal information:

  1. Encryption of all data in transit (HTTPS/TLS)
  2. Firebase Security Rules for access control
  3. Firebase App Check for fraud prevention
  4. Server-side processing of sensitive data via Cloud Functions
  5. Appropriate API key restrictions
  6. Regular security reviews

In addition to the technical measures above, we designate a person responsible for the handling of personal information, provide necessary and appropriate supervision of our employees regarding the proper handling of personal information, and — where we entrust all or part of the handling of personal information to external contractors — exercise necessary and appropriate supervision over those contractors so that they manage personal information securely.

While we strive to protect your personal information, no method of transmission over the Internet or electronic storage is 100% secure. We cannot guarantee absolute security.

11. Legal Basis for Processing (GDPR)

If you are in the EEA, our legal basis for collecting and using your personal information depends on the data concerned and the context in which we collect it:

Legal BasisApplicable Processing
ConsentCollection of birth data for fortune calculations; push notifications
Contract PerformanceAccount management; subscription services; in-app purchases
Legitimate InterestsService improvement; fraud prevention; security
Legal ObligationTax and financial record keeping; responding to legal requests

12. Changes to This Privacy Policy

  1. We may update this Privacy Policy from time to time in response to legal, regulatory, or operational changes.
  2. We will notify you of material changes through in-app notifications or push notifications.
  3. The updated Privacy Policy takes effect when it is posted within the App.
  4. Your continued use of the App after the posting of changes constitutes your acceptance of such changes.

13. Contact Us

If you have questions or concerns about this Privacy Policy or our data practices, please contact us at:

ItemDetails
Company NameGrosbeak Inc.
Data Protection ContactTomonori Hamada
ContactInquiry Form

After you submit the inquiry form, we will review your message and respond in turn (excluding weekends and Japanese public holidays).


Effective: March 31, 2026

Grosbeak Inc.
Representative Director: Tomonori Hamada