Privacy Policy

Required and optional items are listed separately.

• Sign-up (required): email address, password (stored only as a hash that cannot be decrypted), email confirmation code, confirmation that you are 14 or older, and a record of your agreement to the Terms and this Policy (time of agreement and version). The purpose is identity verification and login.
• Features after login (created while you use the service): saved cards and reactions, followed firms, areas of interest, saved glossary terms, and learning and quiz records (Gurumi). The purpose is to let you continue across devices.
• Inquiries and suggestions (optional): the message, the page path you were viewing, browser information (User-Agent) and screen size. If you want a reply, we receive your email address and store it only if you agree.
• Newsletter (optional): email address, the page path and language you subscribed from, time of consent, and version of the consent wording. The purpose is to send the weekly brief and announcements of new features.
• Visit statistics: Cloudflare Web Analytics counts pages, referrers, countries and device types. It sets no cookies and stores no information that identifies an individual; Cloudflare may process IP addresses and similar data temporarily while it produces the statistics.
• Our own anonymous counts: we count, only as daily totals, which kind of visit a subscription prompt started from (a source marker kept in your browser for 7 days), clicks, scrolls and card expansions inside the brief, and the channel a visit arrived from (UTM and referrer host). We do not store email addresses, IP addresses, identifiers or URLs for this.

The service sets no cookies. It keeps your login, learning records and display settings in browser storage (localStorage), which you can clear in your browser settings. When fonts and scripts are loaded from external servers (Google Fonts, jsDelivr and others), your connection information (IP address) may be passed to those providers.

• Member information and feature records: until you leave the service. When you delete your account, the data is deleted immediately, and electronic files are erased in a way that cannot be recovered. Encrypted disaster-recovery backups may keep pre-deletion data for up to 90 days, after which it disappears automatically. If a backup has to be restored, accounts that were deleted are deleted again.
• Inquiries: deleted one year after we finish handling them. A reply email address is deleted immediately when you delete your account or ask us to.
• Newsletter email address: until you unsubscribe.

We do not sell or provide your information to third parties. To run the service we entrust processing to the providers below. All are overseas companies, so your information is transferred abroad.

• Supabase: member authentication and data storage. Country: Australia (Sydney). Items transferred: email address, hashed password, feature records, inquiry content.
• Brevo: sending email and managing subscribers. Country: France and other EU countries. Items transferred: email address, the page path and language you subscribed from, time of subscription consent.
• Cloudflare: delivering the site and visit statistics. Country: United States and others. Items transferred: connection information (IP address and similar).
• GitHub: storing encrypted backups. Country: United States. Items transferred: all of the above information contained in the backups (in encrypted form).

Information is transferred over the network when you use the service. The retention and use periods are the same as those stated above. Each provider's privacy contact is available in its own privacy notice. You may decline the transfer abroad, but then you cannot use features such as sign-up.

You can opt in on the sign-up screen (an optional item) or directly through the subscription form at the bottom of the site, and you can sign up without ticking it. The wording is: "I will receive the weekly brief and announcements of new features by email. I can unsubscribe at any time using the link at the bottom of each email." We record the time of consent and the version of the wording.

Passwords are stored as hashes that cannot be decrypted, data in transit is protected by HTTPS, and backups are encrypted. Access to the database is limited to the operator.

You may ask to access, correct, delete or restrict the processing of your information. On My Page you can check your saved cards, followed firms and Gurumi records yourself. You can delete your account yourself from the account deletion menu on My Page (processed immediately after you re-enter your password). The result of a deletion is recorded only as a time and a success flag; no email address or other user information is kept. Deleting your account erases the account, feature records such as saved cards and followed firms, and newsletter subscription information; for inquiries, only the message text is kept and the email address and reply consent are erased. Send any other request to the contact below and we will handle it within 10 days or tell you why we cannot.

Privacy officer: the service operator. Contact: [email protected]

You can also report or seek advice on privacy violations through the Personal Information Infringement Report Center (dial 118 in Korea, no area code) and similar bodies.

Children under 14 cannot sign up as members. The sign-up screen asks you to confirm that you are 14 or older, and if we learn that information of a child under 14 has been registered, we delete it without delay.

If this Policy changes, we will announce it on the site 7 days before it takes effect (30 days before for significant changes).

Revision history

• November 16, 2026: Added the page path and language you subscribed from to the items collected when you subscribe