Privacy Policy

1-1. Information stored locally (localStorage)

• A randomly generated player ID (12-character alphanumeric)
• Display nickname (optional, entered by the user)
• Selected seal-stamp icon
• BGM and sound effect volume settings

These items live on your device. You can clear them at any time by removing site data in your browser settings.

1-2. Information stored on the server

• Randomly generated player ID
• Nickname and seal-stamp icon
• Elo rating, win / loss / draw counts, total matches, win streak records
• Individual match results (opponent ID, outcome, rating delta)

This data powers the ranking ("番付") feature and matchmaking stat displays. The server backend is hosted on Supabase (described below).

1-3. Information transmitted during gameplay

• Selected genre (pick)
• Per-turn guesses (judged results are shared with the opponent only after submission)
• Tentative picks (shared briefly with the opponent for strategic interaction, only before final submission)

Transmitted content is limited to what is necessary to drive the match. After a match ends, only aggregate stats are retained. All transmissions are encrypted via HTTPS / WSS.

2-1. Hosting and delivery

• Frontend delivery (web build): Vercel Inc.
• Database: Supabase Inc. (Tokyo region)
• Realtime match server: developer-operated host exposed via Tailscale Funnel

These providers may collect access logs as needed to operate their services. Please review their respective privacy policies for details.

2-2. Feedback / bug report form

Reports submitted from the in-app "受付処 (reception)" form are forwarded to the developer's internal Discord channel. You may optionally provide an email address for a reply; doing so is not required.

• Title and body of your message
• Reply email address (only if provided)
• Timestamp

The content is used only to improve the service and is not shared with third parties.

2-3. In-app purchases (planned)

The App currently has no in-app purchases. In the future, paid items may be sold via App Store In-App Purchase or Google Play Billing to support operating costs. This Privacy Policy will be updated to describe how payment information is handled when that occurs.

Payment processing is handled entirely by Apple or Google. The App itself does not receive or store payment credentials such as credit card numbers.

2-4. Advertising (planned)

The App currently displays no advertisements. In the future, an ad network such as Google AdMob may be integrated to support operating costs. This Privacy Policy will be updated to describe how advertising identifiers (IDFA / Android Advertising ID) are handled when that occurs.

A paid option to disable advertisements is also planned.

2-5. Account authentication (planned)

The App currently has no account registration; all activity is anonymous and tied to a randomly generated on-device ID. In the future, authentication methods such as Email, Sign in with Apple, or Google Sign-In may be introduced to support device transfers and persistent rating protection. This Privacy Policy will be updated to describe how authentication credentials are handled when that occurs.