Effective Date: April 25, 2026

Lab Yesterday (hereinafter referred to as the "Company") values the personal information of members of its "Casto" service (hereinafter referred to as the "Service") and complies with relevant laws and regulations, including the "Act on Promotion of Information and Communications Network Utilization and Information Protection."

1. Items of Personal Information Collected and Collection Method

The Company collects the following personal information for membership registration, service provision, payment, and customer support.

• Collected Items:

  • Required: Email address, login identifier (Apple / Google / Kakao social login ID), nickname provided by the social account
  • Member-entered items: Character name, birth date, gender, MBTI, occupation, profile, image; story title, plot, genre, and other creative content
  • Automatically Collected: Service usage records, access logs, cookies, access IP information, device information (model, OS version, etc.), advertising identifier (IDFA/ADID), app crash and error reports, payment receipts, subscription status

  ※ This Service uses the Google AdMob SDK for advertising, and advertising identifiers and device information may be collected during this process.

  ※ This Service uses Google Analytics (Firebase Analytics) for service improvement and usage statistics.

  ※ This Service uses Firebase Crashlytics to collect error and crash information for app stability.

  ※ This Service uses RevenueCat for in-app purchase and subscription management, processing anonymous user identifiers and purchase receipt information.

  ※ For AI-based story and episode generation, this Service transmits creative content entered by the Member (character information, plot summaries, etc.) to the generative AI services of Anthropic, PBC (Claude API) and Google LLC (Gemini API).

• Collection Method:

  • Automatically collected upon membership registration and app usage
  • Directly entered by the Member when creating characters and stories
  • Receipts collected through app marketplaces (Apple App Store, Google Play Store) and RevenueCat upon in-app purchases

2. Purpose of Collection and Use of Personal Information

The Company uses the collected personal information for the following purposes.

• Service Provision: AI-based story and episode generation, character casting, content display and personalization
• Fulfillment of Contract and Payment: Subscription billing and renewal, popcorn top-up, payment history management, refund processing
• Member Management: Identity verification, prevention of unauthorized use, confirmation of intent to join, handling of complaints, delivery of notices
• Marketing and Advertising: Development of new features, analysis of access frequency, statistics on member service usage, delivery of personalized advertisements
• Service Stability: Monitoring and analysis of app errors and crashes

3. Provision of Personal Information to Third Parties and Entrustment

The Company entrusts personal information as follows in order to provide the Service.

• Trustee: Supabase Inc.
  • Task: Database storage and management, authentication services, file storage
• Trustee: Google LLC
  • Task: Google social login authentication; personalized advertising and performance analysis via AdMob; usage statistics and app error/crash analysis via Firebase Analytics and Crashlytics; AI story and episode generation via the Gemini API
• Trustee: Apple Inc.
  • Task: Apple social login identification and authentication token processing
• Trustee: Kakao Corp.
  • Task: Kakao social login identification and authentication token processing
• Trustee: RevenueCat, Inc.
  • Task: In-app purchase and subscription receipt validation, subscription state management