Privacy and cookies

What this notice covers

This notice covers AmirahCo Japanese on japanese.amirahco.us and its Firebase development address, amirahco-japanese-dev-2026.web.app. The main company website has a separate privacy policy. The Japanese app does not require an account, and we do not ask for payment information to practice.

Your learning data

The practice app uses your browser's IndexedDB storage for settings, selected cards, bookmarks, mastery declarations, question drafts, saved runs, answers, review history and measured practice time. It uses this information to resume sessions and calculate your progress. Catalog caches and service-worker storage support loading and offline access to previously available material.

These saves are local to that browser profile and website address. Cloud backup is optional and requires separate sign-in and permission as described below; there is no automatic merging or real-time sync between devices. We do not send the contents of your learning database, answers, mastery, mistakes or backup files to advertising services. Moving to another browser, device or website address does not transfer your save automatically.

Use Save and recovery settings to export a portable backup or restore a file you choose. A downloaded backup can contain your entire learning history; keep it private and share it only intentionally. Clearing this site's browser data removes local saves and caches. Private browsing, browser eviction or a lost device can also remove them. An email to us cannot recover or erase a local save we do not possess.

Hosting and requests

Firebase Hosting, provided by Google, delivers this website and its files. Opening a page or downloading an audio/image file sends normal network information, including your IP address, requested address, browser information and request time, to the hosting service. Those requests are different from the contents of your local learning database. Provider processing and retention are governed by its service policies. See Firebase privacy and security.

Optional visitor analytics is described below. Browser-local participation points and practice statistics remain separate from visitor analytics.

Optional visitor analytics

On japanese.amirahco.us, you can allow Google Analytics 4 to measure visits, sessions and broad navigation categories, and Microsoft Clarity to provide masked interaction recordings and usability statistics. These services receive normal network/device information and may use cookie identifiers after you opt in. They use the existing AmirahCo analytics properties; the Japanese hostname distinguishes this app from our company website. The Firebase fallback, local previews and this privacy document do not load these analytics scripts.

Nothing loads from either analytics provider before your choice. No thanks keeps practice available. Global Privacy Control and Do Not Track keep analytics off. Use Analytics privacy below the practice app to withdraw or change your choice. We stop our events and the recorder without reloading your quiz. If you turn analytics back on after withdrawing during the same visit, it resumes on your next ordinary reload. Revocation cannot undo previously received data or remove cookies on other companies' domains.

Our integration does not read IndexedDB, upload backups, send typed answers or assign personal user IDs. Google events use a fixed practice-page address and a limited section name, not saved-run IDs or search text. Clarity receives page addresses and masked interaction data: the entire page body is explicitly masked, including rendered answer review and custom labels; input contents are masked as well. Query-bearing entry addresses do not start Clarity. Browser-local learning saves are not included in analytics exports. The analytics preference is stored separately as amirahco.japanese.analytics.v1 and is not part of your learning backup.

Google Analytics cookies here use the ja_ga prefix; Clarity can use _clck and _clsk. Withdrawal clears the accessible analytics cookies covered by our integration, not your learning data. Analytics permission does not grant advertising permission. See Google's partner-site processing information, Microsoft Clarity privacy information and Clarity masking documentation. Counts exclude people who decline or block tracking; they are not a count of everyone who visited.

Advertising

The sponsor-supported study guide at amirahco-study-guides.web.app can show one small banner from Adsterra (Ad Market Limited and ADMEDIA LLC FZ). No advertising code is loaded before you choose Allow banner ads. Declining leaves the guide and practice available. We request only one size that fits: 320×50 or 728×90. We do not use popunders, push notifications, interstitials, Smartlinks, Social Bar, automatic refresh or anti-adblock scripts.

If you allow it, your browser contacts Adsterra's account-provided delivery host, bauval.org, and the advertising partners/resources it supplies. They receive network information such as your IP address and browser/device details, the guide's address and ad interactions. Their code may use cookies and similar device storage to deliver and personalize advertising, measure performance, manage frequency and prevent fraud. Collection and retention are controlled by those providers. See Adsterra's privacy policy and cookie policy. We do not receive or copy their third-party cookies.

The advertising guide has a separate browser origin from japanese.amirahco.us. It contains no learner app, catalog, authentication SDK or cloud-backup code. Browser origin isolation prevents its scripts from opening the practice origin’s local learner storage. Our integration does not read or send your answers, learner profile, bookmarks, mastery, backups, sign-in identity or saved sessions to the advertiser. Advertising is confined to that separate sponsored guide; the practice player and this privacy document do not load these ads.

Google AdSense remains pending approval. Its display code and Google's/InMobi's consent diagnostics are not active on normal guide visits. An Adsterra choice is not consent for Google or another network. A future provider change requires a new applicable privacy choice.

Change your ad choice

Use Advertising privacy choices on the guide to allow or turn off Adsterra banners. Both actions are available in the same panel. Withdrawal removes the banner and reloads the guide to unload its advertising code. It does not undo information already received or remove cookies owned by another domain; use the provider's privacy notice for its request/deletion routes.

The choice stays only in this browser and website address, in amirahco.japanese.adsterra-choice.v1, with its notice version, decision date and expiry. It expires after 180 days. Missing, expired, changed-version, corrupt or unreadable records do not authorize advertising. We do not upload this record or include it in learning backups. Another browser/device has its own choice.

An older local ads-off choice, amirahco.japanese.ad-suppression.v1, is still honored. Only an explicit new Allow action removes it. Global Privacy Control or Do Not Track keeps banners off even if an earlier record allowed them. A failed save is reported and keeps this page's banner off; withdrawal can use a no-ad guide address to prevent an old allowed record from reloading a banner. Do not clear all site data to change ads: that could erase local learning progress.

Scrolling, navigating or continuing to use the site never grants permission. This choice does not change analytics, performance diagnostics or cloud backup. It is a direct Adsterra choice, not an IAB TCF consent string or a universal legal-compliance certification.

Contact and your requests

For questions about this service or data you have sent directly to us, email info@amirahco.us. Your email provider and ours process that correspondence. Do not include your complete learning backup unless it is necessary and you intend to share it. Depending on where you live, you may have rights to access, correct, delete or restrict processing of personal information, object to processing, withdraw consent or complain to your local authority. We will address requests relating to information we control; Each named provider supplies controls and contact routes for its own processing.

This app is intended for general adult study and is not designed to collect children's profiles. Changes to the way this site processes information will be reflected in this notice and, where needed, new consent choices. Configuring a consent message does not constitute a blanket legal-compliance certification.

Optional speed diagnostics

The practice app offers a separate Performance privacy control in its footer. Diagnostics are off by default. Allowing visitor analytics does not enable them. If you opt in, Firebase Performance Monitoring receives numeric document/app loading durations, normal network/device information and its own installation identifier. The SDK can store that identifier and configuration in browser storage. This is not anonymous measurement or a count of all visitors.

Our integration sends no answers, card names, search text, learning backups or saved-run identifiers. It runs on a fixed-address, hidden diagnostics page with automatic page/network instrumentation disabled. Only two named loading measurements are sent. It never reads the learner database. Local previews and the Firebase fallback do not start it.

Global Privacy Control and Do Not Track keep diagnostics off. To withdraw, select Keep diagnostics off; this closes the diagnostics runtime without reloading practice or deleting your learning progress. Requests already in flight and data already received cannot be recalled. The separate preference is stored as amirahco.japanese.performance.v1, outside your learning backup. See Firebase privacy and security for Google's processing and retention policies.

Optional cloud backup

Google sign-in connects a private recovery space through Firebase Authentication. It provides an account identifier and basic account information, including your email address, to the app; we do not receive your Google password. Signing in alone does not upload your learner save. Turning on backup separately authorizes uploading the complete save, including preferences, profile label, answers, bookmarks, mastery, review history, practice time and unfinished sessions, to Google Cloud Firestore in the United States (nam5).

Access rules restrict these copies to the signed-in account. They are not public and are not end-to-end encrypted. Google processes identity, network and storage information as our service provider; authorized project administrators can administer the service. Backup contents are not used by our advertising, analytics or performance integrations.

Two browser spaces each retain the latest and previous snapshot, subject to a 700,000-byte encoded limit per copy and shared free-service quotas. Changed saves upload at most once an hour while the app is open, visible and online. The first automatic upload waits for study history, selected cards or saved collections; a settings-only upload requires an explicit action. Work since the last confirmed upload is not backed up yet. Closing the app can interrupt delivery. An oversized save or unavailable quota fails visibly without truncating local history. Keep a downloaded file too.

This is recovery storage, not live synchronization. Restore requires preview and confirmation and replaces the receiving browser's learner save. Before a full restore, the app preserves the current native save in a separate browser-local IndexedDB recovery store. It keeps at most two pre-restore copies, each up to 32 MiB. Failed preservation blocks the restore. These copies remain only on this browser and website address; clearing site data also clears them. They are not uploaded to cloud backup or included recursively inside exported learner files. Save & recovery lets you preview or download them.

Cloud copies remain until overwritten by later snapshots or deleted. In Save & recovery, Advanced controls lets you turn off automatic uploads, sign out or delete all cloud copies. Turning off or signing out does not delete copies; deleting copies does not erase local progress or the authentication account record. Turn off uploads on other devices too if you do not want them to upload again. For account-record deletion or other requests, contact info@amirahco.us. Provider operational retention is described in Firebase's privacy information. Clearing browser data alone does not delete a cloud copy, and recovery is possible only if an upload was previously confirmed.