Privacy Policy

Nihongo Circle is a free Japanese-study website operated by an individual. For privacy questions, message @meltenx on X, or email techspacewizard@gmail.com. We control the account, learning and cosmetic records held by the Service. Our providers have the roles described below; Stripe and Link also handle their own merchant and payment functions.

• Account information — handled by our authentication provider, Clerk: your email address, name, profile image, and any social-login identifiers you choose to connect.
• Profile — a public handle, display name, optional bio, and avatar. If you upload your own avatar, we store that picture (cropped and resized in your browser first) and show it on your public profile until you remove or replace it.
• Learning data — your review schedule and history, challenge scores, daily activity and XP, streaks, badges, quests, and study preferences (such as your target exam date and chosen JLPT level).
• Preferences — theme, skin, audio voice and speed, cosmetic selections, and similar settings, stored in your browser’s local storage and/or your account. Your private cosmetic preview switches do not save selections to your account. Refunding a pack does not clear its saved selections, but those selections have no effect unless you own the pack again.
• Content you submit — bug reports, suggestions, friend requests and support messages. Optional community-poll answers are linked to your account to prevent duplicate votes; the results shown to admins are totals. If you email us about a purchase, we receive the contact details, purchase reference and message you choose to send.
• Audio text — when audio is generated, the Japanese text to be spoken is sent to our text-to-speech provider (Microsoft Azure) and the resulting audio file is cached. We don’t send your personal information for this.
• Missed answers, when you ask for an explanation — pressing “Why is that?” after a wrong answer sends the word, its meaning and example, and what you typed, to our AI provider so it can explain the difference. Your name, email and account ID are not sent — the request carries the word and the answer, nothing that identifies you. The resulting explanation is cached against that word and answer and reused for anyone who makes the same mistake, so a common wrong answer is only ever explained once.
• Technical & usage data — standard server logs (including IP address and browser/device info, processed by our hosting providers) and product analytics (pages visited and feature events such as completing onboarding, processed by PostHog on our behalf). We also keep a per-account daily count of audio generations to prevent abuse.

When analytics is allowed in this browser, we also record optional signed-in quiz starts and finishes, pass/save requirements, and save attempts, acknowledgements, retries and optional post-save errors in our database. These contain account and random attempt identifiers, lesson identifiers, release/environment and broad status categories; they contain no typed answers, card identifiers or raw error details. Raw observations have a 90-day retention period and are pruned daily. Declining analytics stops new observations; events missed before permission are not replayed. Existing learning progress remains necessary to provide your account.

If you submit a withdrawal statement, we separately record your name, acknowledgment email, purchase identification, statement, server receipt time and request reference. These records do not require an account and are not erased automatically when an account is deleted. We use them to handle the request, demonstrate when it was received and meet consumer-rights and recordkeeping obligations. We retain them while needed for those purposes and applicable legal requirements. Resend processes the statement and contact details to send your acknowledgment and notify purchase support. We also keep email attempt and provider-acceptance information so failed acknowledgments can be retried. Provider acceptance does not prove inbox delivery.

To confirm purchases and manage access, our cosmetic purchase records contain your account ID, pack ID, test or live environment, Stripe account reference, internal order ID, Checkout Session, payment and line-item and webhook event identifiers, payment and delivery status, RevenueCat purchase and entitlement references, and timestamps. These records do not store card numbers, billing addresses or the contact email you enter at checkout. They are separate from your learning history.

When you open checkout, we send Stripe internal purchase identifiers and pack references, including your account ID, so a confirmed payment can be matched to your account. You provide payment and contact information directly to Stripe and Link on their hosted checkout. Stripe Managed Payments uses Link as merchant of record. Stripe and Link act as independent data controllers for their own merchant and payment functions, including transaction support, fraud prevention and legal obligations. Their processing is explained in the Stripe Privacy Policy and the Link Privacy Policy.

RevenueCat receives your account identifier and purchase references through Stripe notifications to associate the purchase with your signed-in account and verify cosmetic ownership. We keep a local ownership record so delivery can be checked and retried. Cosmetic ownership and Pro ad removal are separate entitlements.

We use purchase records to verify ownership, prevent duplicate fulfillment, handle refunds and disputes, and respond to purchase questions. Essential purchase processing and ownership checks are needed to provide your purchase and do not depend on optional analytics consent. For help, see purchase support.

• Provide the Service and your account, and schedule your reviews.
• Show your progress, streaks, badges, and — if you take part — leaderboards.
• Generate and cache pronunciation audio.
• Respond to your reports and improve the Service.
• Keep the Service secure, prevent abuse, and enforce rate limits.

We rely on your consent and our legitimate interest in running the Service, and on performing our agreement with you (these are the legal bases where laws such as the GDPR apply).

We don’t sell your personal data. We use the following providers to run the Service. Some process data on our behalf; payment providers also have their own responsibilities as described above:

• Clerk — authentication and account management.
• Supabase — database and storage for your account and learning data.
• Vercel — application hosting and aggregate, privacy-friendly analytics.
• PostHog — product analytics (how features are used), so we can improve the Service. Used for our own product decisions only.
• Microsoft Azure — text-to-speech generation.
• Vercel AI Gateway — routes explanation requests to the model that writes them (MiniMax M3, served by GMICloud). Sent only when you ask for an explanation, and only the word and the answer you gave.
• Cloudflare R2 — storage of generated audio files and avatars you upload.
• RevenueCat — purchase association and entitlement verification for cosmetics, and Pro subscription entitlement management. They receive account and purchase identifiers needed to verify ownership. We never receive or store your card number.
• Stripe and Link — hosted checkout, merchant-of-record services and transaction support for optional cosmetic purchases, as described under Cosmetic purchases.
• Google / Gmail — delivery and storage of messages sent to our published Gmail contact address, including purchase-support and privacy requests.
• Resend — transactional withdrawal acknowledgments and purchase-support notifications. It receives the request statement and the contact details necessary to send those emails.

We may also disclose data if required by law or to protect the Service’s and users’ rights and safety.

Your handle, profile, and progress can appear on your public profile page and on leaderboards. You can hide yourself from the global leaderboard in Settings. Friend connections are visible to the people involved. Cosmetic items you choose to display can appear on your public profile, including a mark identifying paid support. Purchase identifiers and payment records are not displayed publicly. The wardrobe preview is visible only to you.

We use three kinds of browser storage:

• Necessary — cookies that keep you signed in (set by Clerk), and local storage for preferences like theme, skin and audio settings. These can’t be turned off without breaking the Service.
• Analytics — first-party PostHog storage (a cookie plus local storage) that tells us which features are used. In the EEA, UK and Switzerland we ask before loading this, and it stays off until you say yes. Everywhere else it’s on by default and you can switch it off in Settings → Privacy. Switching it off also clears what was already stored in your browser.
• Advertising — see the next section.

Nihongo Circle is free to study with and always will be — no learning feature is ever locked behind payment. Advertising is how that gets paid for. An optional Pro subscription removes ads; it doesn’t unlock learning tools or content. Cosmetic purchases change appearance only and are separate from Pro.

Today, the only ads we show are our own. They are plain links to other parts of this site. They set no cookies, load nothing from third parties, and involve no tracking or profiling whatsoever.

If we ever introduce a third-party ad network, we will update this policy and name the provider before the first ad appears, and — where consent is required — ask for it first. We will never sell your personal data, and we will never share your learning data with advertisers.

Ads never appear inside a review session or a timed round. They only appear on reference pages and at the end of a game.

We keep your account and learning data for as long as your account is active. If you delete your account, we delete the associated data, except where we need to keep limited records to comply with law or resolve disputes. Cached audio is keyed to the text spoken, not to you.

Our cosmetic order and payment-event records are removed when your account is deleted, along with access to account-bound cosmetics. Deleting your Nihongo Circle account does not delete Stripe or Link’s own records. They retain data under their own policies and applicable payment, legal and dispute-handling requirements. Support correspondence is held separately from your app account for as long as needed to handle your request and any related legal or payment issue. Account deletion does not automatically erase those messages; contact us about a deletion request.

Depending on where you live, you may have the right to access, correct, export, or delete your personal data, and to object to or restrict certain processing. You can edit much of your profile and preferences in-app, and you can request the rest by messaging @meltenx on X or emailing techspacewizard@gmail.com.

You can withdraw consent for analytics using Your privacy choices above, or in Settings → Privacy when signed in.

The Service isn’t directed to children under 13, and we don’t knowingly collect their data. If you believe a child has given us personal data, contact us and we’ll remove it.

Our providers may process data in countries other than yours, including the United States. Where required, we rely on appropriate safeguards for those transfers.

We take reasonable measures to protect your data — see our Security Policy. If we change this policy, we’ll update the “Last updated” date above and note material changes in-app where practical.