Privacy Policy

• To identify your account and provide the service (calculating your saju information and generating/delivering daily, weekly, and monthly letters)
• To send push notifications
• To process subscription payments and prevent free-trial abuse
• To generate a personalized reply in the "Today's Story" feature
• To respond to customer support inquiries
• To send marketing emails (only to users who have explicitly opted in) and to generate Lunar New Year readings
• To analyze usage, improve the service, respond to errors, and prevent abuse (bots/spam)

We delete your information immediately when you close your account or when we receive a deletion request — there is no additional grace period or delay.

Your birth date and birth time; the text you write in the "Today's Story" feature and its reply; the notes you enter in compatibility-sharing or deep compatibility to tell people apart; the free text you submit for a Lunar New Year reading; and the messages you send through Support are all stored encrypted (AES-256). Calculated results (day master, month branch, hour branch) are not personally identifying on their own, so we store them without encryption.

Where law requires longer retention (e.g., payment records), we retain that data only for the legally required period before deletion.

We share data with the following third parties only as needed to provide the service:

• Firebase / Google Analytics (Google): authentication, push notifications, and usage analytics for both the app (Google Analytics for Firebase, production builds only) and this marketing site (a separate web stream in the same GA4 property)
• RevenueCat: subscription status management (actual payment is processed by Google Play Billing; we do not store your card or payment details ourselves)
• Our AI content provider (currently OpenAI; may be Anthropic or Google depending on configuration): generates the wording of your letters and "Today's Story" replies, as well as the home mini demo and Lunar New Year readings on our marketing site (saju-letter.com). This may include your calculated saju values, the text you write in the "Today's Story" feature, and the name and free text you submit for a Lunar New Year reading.
• Cloudflare Turnstile: bot and spam prevention on our marketing site's public submission forms (your browser information is sent to Cloudflare while the widget is active)
• Resend: sending marketing emails and Lunar New Year result emails
• Sentry: crash and error monitoring

A friend who opens a compatibility link you share does not need to create an account — they only enter their name and birth date. The saju chart is calculated entirely on their own device or browser. We store the resulting heavenly stems and earthly branches (year, month, and day pillars) together with the name they enter. We also receive their Gregorian date of birth (year, month, day) only to confirm they are 16 or older, and we do not store that date. The name is used only to display it on the result screen and is not used for any other purpose.

You can delete your account yourself at any time from the app's Settings screen. Deleting your account immediately replaces identifying information (name, email, gender, birth date and time) with anonymized values and signs you out for good, and cancels auto-renewal if you have an active subscription — but any remaining paid time is not refunded. If you just want to stop future charges while continuing to use the app, you can cancel only your subscription from the app's Settings screen instead of deleting your account. If you no longer want to receive marketing emails, you can opt out anytime using the unsubscribe link at the bottom of each email. After a cancelled subscription reaches the end of its paid period, your account reverts to the free tier and subscription-only features are locked again. For any other requests — such as accessing or correcting your information — please contact us using the information below.

• Sensitive information — including birth date, birth time, "Today's Story" text and replies, compatibility/deep-compatibility notes, Lunar New Year free text, and Support messages — is stored using AES-256 encryption
• Encryption keys are managed through a dedicated key management service (KMS) and are never hardcoded
• Access to the admin panel requires separate authentication

This service is intended for users aged 16 and older. We verify this using the Gregorian birth date you provide during app onboarding and when submitting public pages (compatibility sharing, the home demo, and Lunar New Year). Birth dates sent only for that age check on public pages are not stored. We do not knowingly collect personal information from children under 16. If we become aware that a child under 16 has used the service, we will take appropriate steps to delete the relevant information promptly.

For privacy-related questions or requests to access, correct, or delete your information, please contact us at:

Email: contact@mikomaru.com

This policy is effective as of July 29, 2026, and may be updated as our practices, applicable laws, or the service itself change (most recently updated: September 13, 2026). We will notify you of material changes through the app or this page.