Privacy Policy

GETTYS L JASON (trade name: Jason Kobayashi), a sole proprietor, runs PeraNabi Study (formerly Mastermind Japanese) and is responsible for your personal data.

Address: RJ3, 2-16-12 Jiyugaoka, Meguro-ku, Tokyo 152-0035, Japan.

Privacy contact: support@peranabi.com.

You can email this address without an account or a working sign-in.

We are based in Japan and have not appointed a representative in the EU or UK. For any privacy matter, contact us directly; you can also complain to your local data-protection authority (section 9).

• Account: your email address (your account contact for sign-in and account notices), an optional password (stored only as a hash), your internal account identifier, account handle, display name and avatar color, and, if you use Google sign-in, Google’s account identifier and your verified Google email. We do not store your Google name or profile photo.
• Study data: your answers, grades, response times, confidence ratings, progress, session history, saved items, kanji writing progress, settings, and “Was this helpful?” ratings.
• Speaking practice (optional): your microphone audio is processed on your device and is never uploaded. The text it recognizes, the target phrase, scores, error details, timing, session and attempt identifiers, and basic details about the attempt (such as browser type and the speech model used) may be sent to PeraNabi Study.
• Feedback: the type, area, message and study context you send from the Feedback page, and any screenshot you attach. Screenshots are private: only you and the operator can open them. Before upload, your browser re-encodes the image (shrinking it if it is large), which drops embedded details such as camera location data.
• Support requests: your reply email, category, impact, subject, message, and, if you include them, the page and browser details, plus an account association when you are signed in. Support content and your reply email may also be delivered to the operator by email.
• Technical data: your IP address, browser information, and request times, used to run and protect the service. Records of sign-in abuse checks keep only hashes of your IP address, browser details, and email address and account identifiers. Our own study-error telemetry records the route (without its query or fragment), error kind, response status and optional session identifier. We do not record your screen with session replay.
• Recognised browsers: for each browser you sign in with, a hash of the value its __Host-mastermind_device cookie holds for your account, with when it was first and last used. It lets that browser keep its own allowance of sign-in codes and sign in with your password without an email code. It contains no browser details, IP address or location.
• Product-update emails: whether you opted in, and when.
• Payments, if enabled: Stripe handles payment details. PeraNabi Study keeps customer, subscription and transaction identifiers, amounts, currency, and payment and access status. We do not store full card numbers. Paid sales are currently off.

An email address is required to create an account. We automatically process the technical data needed to deliver and protect the service, and when you use study features we process the answers and progress needed to provide them. Passwords, speaking practice, feedback, support requests, and product-update emails are optional; some information is required if you choose those features.

Where the GDPR or UK GDPR applies, these are our Article 6 lawful bases:

• Contract (Article 6(1)(b)): create and secure your account, provide study and optional speaking features, choose what you practice, show your progress, sign you in or link Google when chosen, answer account and service support questions, send essential account emails, and manage payments if enabled.
• Legitimate interests (Article 6(1)(f)): deliver public pages, keep the service secure, prevent abuse and fraud, fix errors, and review feedback and learning-quality records to improve PeraNabi Study. You may object where applicable law provides that right.
• Consent (Article 6(1)(a)): record your optional product-update email preference and send updates only if you opt in. You can withdraw at any time in Settings; withdrawing does not affect processing before then. We are not sending these yet.
• Legal obligation (Article 6(1)(c)): keep required accounting records, respond to legally required privacy requests, and comply with lawful demands.

Microphone access also requires your browser permission; you can stop speaking practice or revoke that permission.

Our study scheduler automatically chooses what you practice next; this has no legal or similarly significant effect on you.

We do not sell your data, use it for advertising, or send your account data or study progress to AI providers.

These service providers process data for hosting, storage, delivery and security on our behalf:

• Render (a United States company): runs the app on servers in Singapore and captures its service logs. Error records (section 7) are stored on those Singapore servers. Render’s terms say its primary processing operations take place in the United States.
• Supabase (Supabase Pte. Ltd., a Singapore company): hosts the database, including feedback screenshots, on servers in California, United States. Supabase and its own service providers may also process data outside that region for support, security, and operations.
• Cloudflare (a United States company): delivers and protects traffic to the site through its data centers worldwide, usually the one nearest you.
• Resend (a United States company): sends sign-in, account, and support emails, including support content delivered to the operator.

The app runs on servers in Singapore, and our database is hosted in California, United States. Other processing can take place outside Japan or your country through our providers’ support, security, and delivery operations, including Cloudflare’s worldwide network. The providers are based in the United States and Singapore. The United States has no comprehensive federal privacy law like Japan’s, though several states have their own privacy laws. Japan’s Personal Information Protection Commission publishes information about the privacy systems of the United States (https://www.ppc.go.jp/enforcement/infoprovision/laws/offshore_report_america/) and Singapore (https://www.ppc.go.jp/enforcement/infoprovision/laws/offshore_report_singapore/).

Japan has EU and UK adequacy recognition; this does not cover every onward transfer to another country. Standard contractual clauses bind a recipient to data-protection safeguards. Render, Supabase and Resend publish processing terms with those clauses and applicable UK transfer arrangements. Published terms alone do not establish which agreements cover our accounts or every onward transfer. We review provider arrangements at least once a year. You can ask us about the destinations and applicable safeguards.

Provider terms: Render DPA, Supabase DPA, Resend DPA.

For transfers out of Japan, APPI Article 28 requires a recognised destination, a recipient that continuously maintains equivalent protections, informed consent, or an applicable statutory exception. Outsourcing alone does not remove this requirement. Complete provider processing locations and agreement coverage still need confirmation; we do not claim that every foreign transfer is covered by adequacy or consent. You can request information about these arrangements.

If you use Google sign-in, Google (a United States company) receives your sign-in request directly from your browser and handles it under Google’s own privacy policy (https://policies.google.com/privacy). Google is not our processor.

Hugging Face serves optional speech-model downloads under its own privacy terms (section 5). If payment features are enabled, Stripe receives your email, purchase information and internal payment identifiers and handles payment data under its own privacy terms (https://stripe.com/privacy). These optional providers are not all processors acting only on our instructions.

Beyond these providers, we disclose personal data only when the law requires or permits it, for example to comply with a legal order or to protect someone’s life, safety, or property. If PeraNabi Study is transferred to a company we set up or to a successor, your data will move with it under this policy, and we will tell you on the site before that happens.

Fonts are hosted by PeraNabi Study and do not contact Google. The speech runtime is also hosted by PeraNabi Study. Your browser connects to these optional services only when you choose the relevant feature:

• Google: only when you choose Continue with Google to sign in or link your account. The button takes you to Google’s site; no Google sign-in script or One Tap prompt runs on PeraNabi Study. Google receives your IP address, browser information, sign-in request and its own browser session details, and returns a signed ID token to PeraNabi Study for verification. Google handles its data under its privacy policy (https://policies.google.com/privacy).
• Hugging Face and its download providers: only when you open speaking practice, to download the speech model to your device. They receive your IP address, browser information and requested file address to serve the download. Neither microphone audio nor recognized words are sent to Hugging Face by PeraNabi Study. Hugging Face handles it under its privacy policy (https://huggingface.co/privacy).

Nothing is sent to these services to track you.

• The essential first-party __Host-mastermind_refresh cookie renews sign-in. It is HttpOnly, sent only over HTTPS (except when the app runs on a developer’s own computer), and normally lasts up to 30 days.
• The essential first-party __Host-mastermind_device cookie holds a random value for each account that has signed in with that browser, so we can recognise the browser for that account (see section 2). It is HttpOnly and sent only over HTTPS (except when the app runs on a developer’s own computer). Your browser keeps it for up to about 13 months, but we stop recognising it 180 days after its last use. It is not used for tracking or advertising.
• Your browser’s session storage holds your current sign-in token and unsaved study work; while you sign in with an emailed code, the email address and that code request’s identifiers and send times (removed when you sign in or start over; the codes expire after 15 minutes); and one-time Google redirect state (removed when you return from Google; it expires after 10 minutes). Your browser normally clears session storage when you close the tab. Older sign-in tokens found in local storage are moved there once and removed. We do not persist the Google ID token.
• Local storage keeps preferences (such as theme, reading support, microphone, daily goal and study options), your last sign-in method, release acknowledgments, quick-practice selections, summaries of recent study sessions, and information used to recover an interrupted speaking attempt. Your browser also caches app assets and speech-model files.
• Google may use its own cookies after you navigate to its sign-in page. Cloudflare may use security cookies when its protection features require them.

Account deletion cannot remotely erase what is stored on your devices; you can remove it by clearing this site’s data in your browser. Clearing it can remove local progress and preferences, sign you out, and require another model download. We use no cookies for analytics, advertising, or cross-site tracking, and no third-party analytics or ad trackers.

• Account and study data, speaking attempts, feedback (other than screenshots) and linked support requests: while your account exists; inactivity alone does not automatically delete them. Account deletion removes these records, including support records matching your current account email. You can ask us to delete feedback sooner.
• Feedback screenshots: kept in our database. 180 days after you send one, it becomes eligible for automatic deletion and is removed by our scheduled cleanup. Deleting your account removes them with your other records, and you can ask us to delete them sooner.
• Your email-update opt-in: until you opt out or delete your account. Opting out does not remove the contact email needed for sign-in and account notices.
• Support requests are also delivered by email to our support mailbox. Account deletion removes the copies in our database; mailbox copies are deleted when you ask, and otherwise kept only as long as needed to handle follow-up.
• Support requests sent without an account: as long as needed to resolve them and handle any follow-up.
• Sign-in abuse records (hashed identifiers only): 12 months.
• Recognised-browser records: up to 180 days after the browser was last used. Forgetting a browser in Settings stops recognising it at once, and account deletion removes all of them.
• Error records on our server: deleted within 2 days. Server logs kept by our hosting provider: no more than 30 days.
• Our email provider keeps copies of the emails it sends, and its logs, for 30 days for delivery and abuse prevention.
• After account deletion, we keep a minimal deletion record so we can show that we honored the request: a hashed copy of your email and account ID, your account handle, the request and completion dates, and a deletion reason, any support reference and operator notes. We remove it 24 months after the request is completed or cancelled. A cancelled deletion request also leaves this record.
• Payments, if enabled: a minimal accounting ledger with amounts, dates and Stripe transaction identifiers is kept for seven years from each transaction, with expired rows purged. Local Stripe webhook records are retained with identifying fields removed during account deletion. Stripe identifiers may still be linkable to a person through Stripe; these records are not anonymous. Stripe customer deletion or redaction happens after local deletion and can require follow-up.
• Hosting and network logs, delivered email, mailbox copies and provider backups can remain separately after database deletion. The support mailbox provider, complete provider-copy retention and active backup arrangements still need confirmation; we cannot promise that all retained copies disappear with your account.
• Encrypted copies held by the operator: for maintenance, and to check how well PeraNabi Study predicts what you remember, we may take an encrypted copy of our database and keep it on the operator’s own computer. Each copy is deleted when it is no longer needed, and automatically 14 days after it was taken by a deletion service on the operator’s computer, which checks every ten minutes while it runs and again when it starts; if that service is not running at that point, the copy stays encrypted until it runs again. If you delete your account while a copy exists, your data stays in that copy until the copy is deleted. A copy is restored over our live database only to recover from data loss, and only after every account deletion made since it was taken has been applied again. AI tools never read these copies; they see only summaries of them that describe no individual learner.
• Records the law requires us to keep may be kept longer, in minimal form.

In Settings, “Download my learning history” gives you a copy of your study data. “Request account deletion” starts deletion: after you confirm by email, your account is locked and is permanently deleted 14 days later; you can cancel during those 14 days.

The learning-history download is not a complete copy of every personal-data field. Email support@peranabi.com to request other account information.

You can ask us to disclose, correct, add to, delete, stop using, or stop sharing your personal data, and to tell you how it is handled. Japan’s Act on the Protection of Personal Information gives you these rights; if the GDPR or UK GDPR applies to you, you can also restrict processing, object, and receive your data in a portable form. Where applicable, you can also ask for third-party provision records under APPI and object to processing based on legitimate interests. Email support@peranabi.com with your request and the account email concerned; you do not need to sign in. We may confirm your identity first, and for formal requests may ask for more verification in proportion to the data involved. There is no fee. We respond without undue delay and normally within one month of receiving your request. If we need information to verify your identity, we will ask promptly; any extension follows the applicable law, and we will explain it to you.

Complaints: email the same address. You can also contact Japan’s Personal Information Protection Commission or, if you are in the EU or UK, your local data-protection authority.

• Policy: we use personal data only for the purposes above.
• Rules: we follow written rules for handling personal data, security incidents, and account operations.
• Organization: the operator is responsible for data protection, handles any incident, and reports it where the law requires.
• People: only the operator can access personal data in our systems; there are no staff or contractors.
• Physical: data is stored in our providers’ secured data centers. An encrypted copy may also be held for a limited time on the operator’s own computer (see section 7). Access to the devices and accounts used to run PeraNabi Study is restricted.
• Technical: encrypted connections (HTTPS), hashed passwords, access controls, network-restricted admin access, masked email addresses in logs, account handles instead of email addresses in product and operator views where practical, automated checks for vulnerable dependencies on every build, and periodic security reviews.
• Foreign countries: we have checked the privacy systems of the United States and Singapore, where our providers are based and process data (see section 4).

No system is perfectly secure, and we cannot guarantee absolute security.

PeraNabi Study is a general-audience Japanese-learning service and is not directed to children. If you believe a child has supplied personal data, contact us so we can investigate and handle it.

We send sign-in, account, and support emails because your account needs them. We do not send product-update emails yet. If you have opted in and we start sending them, each email will say who sent it and how to stop, and you can also turn them off at any time in Settings.

When we change this policy, we update the version and date above and record the change in the changelog. For significant changes we will also tell you on the site before they take effect.