やくそく。

Who we are

Shiro is run by Jakub Retek, based in the Czech Republic, in the European Union. For anything in this policy ・ a question, or to use one of your rights below ・ write to support@kitsune-bi.com. We are the data controller for the information described here.

Your learning data stays on your device by default

Progress, streaks, mistakes, reviews and settings are stored locally on this device. You can use every part of Shiro without an account, and if you never make one, it stays on your device ・ with three exceptions you start yourself, each described here: moving to the Home Screen app, sending a report, and web reminders. Delete the app and that data is gone with it.

ホーム画面へ移す ・ moving your progress to the Home Screen app uploads your whole backup (your progress, your name and what Shiro remembers) to our server (Cloudflare) under an eight-character code. It is held for at most ten minutes and deleted the moment the other app confirms, or at expiry. It is never read for anything else.

報告 ・ a report you send from the app is kept on our server for 90 days: your words, the kind of report, the reply address if you gave one, the build you were on, the screen you came from and the item you were looking at. Nothing else is attached and it goes to no third party.

The launch list

If you leave your email on our page to hear when Shiro opens, we keep that address and the time you left it on our server (Cloudflare), and use it for one thing: to tell you when Shiro launches. We send you that email and nothing else ・ no marketing, and the list is shared with no one except the service that delivers that email (Resend). We keep it because you asked us to (in legal terms, your consent), and you can take that back at any time: write to support@kitsune-bi.com and we remove your address, and the launch email itself has a one-click way off the list. The list is deleted 30 days after the launch email goes out, or by 31 December 2027 if Shiro has not launched by then.

If you make an account, we hold what it takes to sync

An account is optional and exists so your progress can follow you to another device. When you make one we store your email address, the name you give us, and a copy of your progress data on our servers (Cloudflare, in their global network). We do this to provide the account you asked for ・ in legal terms, to perform our contract with you.

We sign you in with a one-time code by email, through Resend, our email provider. There is no password. We do not sell your data, and we do not send marketing unless you ask us to.

You can delete your account and everything attached to it from 私 (Me) at any time. Deletion is immediate and permanent.

Shiro is an AI ・ and his voice and the artwork are AI-generated

Shiro is an artificial-intelligence tutor. When you chat with him, you are talking to a computer program, not a person. His spoken voice is generated by an AI voice service (ElevenLabs), and the illustrations throughout the app ・ the word and kanji stickers, the scenery ・ are AI-generated images. We tell you this plainly because you deserve to know what is real.

The camera Lens and talking with Shiro use an AI service

When you point the 写 Lens at something or talk with Shiro, that photo or message is sent to Anthropic (our AI provider, in the United States) to generate the answer. Anthropic does not use it to train its models and keeps it only briefly; Shiro keeps no copy off your device. In 話す Speak your microphone audio is streamed live to Google (Gemini) so the teacher can hear and answer you; the transcript of the talk stays on your device and only that transcript is sent to Anthropic for the written notes.

For the Lens: the camera’s live picture stays on your device. When you tap, we send one small still picture (at most 1024 pixels on its long side) and your course level, and nothing else. Our server passes the picture to Anthropic and keeps no copy of it. Shiro never says who a person in a picture is. When the picture shows a well-known thing (a product, a fictional character, a landmark) and nobody is in it, the lesson about that thing is written from its name alone, never from your picture, and kept on our server for up to 30 days to show other learners who point at the same thing. To keep the yearly Lens allowance, our server counts uses per device (a random id made on this install, not your name) and per network address: a daily count, kept for a day, and a yearly count, kept for up to two years.

When you talk with Shiro we also send what he needs to answer you as your tutor: your first name if you gave one, your level and JLPT target, the things Shiro remembers about you, and the points you have been getting wrong. You can see and delete everything Shiro remembers on his own screen. We never send anything you did not type, photograph, or tell him.

The Lens is for adults ・ please do not photograph children with it.

Speaking practice

When you record yourself in 声 Shadowing, the recording stays on your device so you can play it back against a native voice. To tell you whether you said the right words, the audio is transcribed・on most browsers this happens through the browser’s own speech service, and where that is unavailable it is sent to our transcription provider (ElevenLabs) and discarded immediately. No recording is ever stored by us.

Who else touches your data, and where it goes

A few trusted providers process data on our behalf so the app can work: Cloudflare (hosting and the account database), Resend (the login and account emails), Anthropic (the AI answers and the written notes after a spoken lesson), Google (the live voice conversation in 話す Speak ・ your speech is streamed to Google’s Gemini service in real time to hear and answer you, and is not kept by us), ElevenLabs (Shiro’s recorded voice and speech transcription), and Stripe (payments, when live). Each is bound by a data-processing agreement.

見る Episodes: when you search for an anime or manga, the app first looks in a list of popular titles it carries on your device. Only when that list has no good match does our server send the title you typed to Wikidata, a free public database run by the Wikimedia Foundation, and keep the answer in its cache for up to a day. Wikidata receives the search text and our server’s address, never yours, and nothing else about you. If nothing matches and you type a show in yourself, its name and your episode number go to Anthropic so Shiro can open the talk; that opening card is written for you alone and is not stored or shared by us. When you talk an episode over with Shiro, what you type and the recent lines of that talk go to Anthropic to write his reply, and are not kept by us; the talk itself is kept on your device. The episode cards Shiro opens a listed show with are written once per episode and level and shared with every learner who picks the same one: they hold only the catalogue’s titles and Shiro’s text, nothing about you. Our server counts how many turns your device has used (by its random id, with no text; a show you typed in is counted with no trace of its name), so the daily and yearly allowances hold. The older episode debrief this replaced looked titles up from your browser at AniList and Jikan (an open interface to MyAnimeList); it is being retired.

AI use: so that the AI stays within what a subscription pays for, our server keeps, per device (by its random id, not your name), how much this month’s AI calls cost and on how many days the device used AI. Nothing you typed, said or photographed is kept with it. The month’s total is deleted when the month ends; the count of days is deleted 30 days after the device last used AI. Your network address is counted only for the day, like every daily count.

Some of these are in the United States, so some data leaves the EU. Those transfers rely on the EU–US Data Privacy Framework or the European Commission’s Standard Contractual Clauses. You can ask us for the details.

No ads, no trackers, no analytics SDKs

Shiro contains no advertising, no third-party trackers, and no analytics SDKs. When you have an account we record which screens are used, tagged with a random id made on this install ・ pseudonymous, not anonymous: it identifies the install, not you, and carries no name, no email and no learning data. Without an account nothing is sent.

The 根付箱 charm box shows what share of travellers own each charm. Once you have opened the box, the app sends our server (Cloudflare) the list of charms you hold, at most once a day, and nothing else: no device id, no name, no other learning data. The server adds it to counts per charm and a count of travellers active in the last 30 days, and keeps nothing else: no list of anyone’s charms, and not your network address (it is used only in the moment, to slow a flood of reports, and never written down). So that tomorrow’s report replaces today’s instead of counting you twice, the server hands back a single-use receipt that stays on your device; the server keeps only the fact that a receipt was used, as a random code, for up to 30 days. The shares shown are refreshed once a day, so no single report can be picked out of them, and below 200 travellers no share is shown at all.

Reminders in the installed app are local notifications: the hour stays on your device. Reminders in the browser use web push: to send one, our server (Cloudflare) keeps this browser’s push address and keys, your chosen time and time zone, when the next one is due, the last day one was sent and counters of sends and failures. The message itself is sealed so only your browser can read it. Turn reminders off in Me and that record is deleted.

Payments

Subscriptions are handled by our payment provider, Stripe・your card details go straight to Stripe, and Shiro never sees or stores them.

How long we keep it

We keep your account data for as long as your account exists. Delete your account and it is gone immediately. Usage events are kept only in aggregate; a report for 90 days; the Lens’s use counts for a day and a year (up to two), a device’s AI use for the month until the month ends and the days it used AI until 30 days after its last use, and a shared Lens lesson about a thing for up to 30 days; a move-to-Home-Screen backup for at most ten minutes; the charm box’s owner counts and used receipts for 30 days; a browser’s reminder record until you turn reminders off; the launch list until 30 days after the launch email.

Your rights

You can ask us to show you the data we hold, correct it, delete it, or send you a copy to take elsewhere; you can object to a use or withdraw a consent at any time. Most of this you can do yourself from 私 (Me); for the rest, write to support@kitsune-bi.com and we will answer within a month.

If you think we have handled your data wrongly, you can complain to the Czech data-protection authority, the Úřad pro ochranu osobních údajů (uoou.gov.cz).

Children

You need to be at least 15 (the age set in the Czech Republic) to make an account on your own; younger than that, a parent or guardian needs to agree. We do not knowingly collect data from children under that age, and the camera Lens is for adults. If you believe a child has made an account, write to us and we will remove it.

What Shiro is

Shiro is a study tool for Japanese from your first kana to JLPT N1. We work hard to keep the content accurate, but no app can guarantee an exam result・the walking is yours. It is a study aid, not professional or exam advice, so please double-check anything that matters.

Not affiliated with the JLPT

JLPT® and “Japanese-Language Proficiency Test” are trademarks of the Japan Foundation and Japan Educational Exchanges and Services (JEES), used here only to describe what Shiro helps you study. Shiro is an independent study aid and is not affiliated with, endorsed by, sponsored by, or connected to them. The practice tests are original materials we wrote ・ they are not official JLPT examinations, and a score here is not an official JLPT result. Always confirm exam dates, sites and registration on the official jlpt.jp.

Shiro and the artwork are AI-generated

Shiro is an AI tutor, his voice is AI-generated (ElevenLabs), and the app’s illustrations are AI-generated images. AI can be confidently wrong ・ treat Shiro as a helpful study partner, not an authority, and verify anything important.

What’s ours, what’s yours

The app, its lessons, stories, artwork and audio are ours or licensed to us・please do not rip, resell or redistribute them. Your progress is yours.

Open data we build on

Dictionary and kanji data derive from JMdict, JMnedict and KANJIDIC2, property of the Electronic Dictionary Research and Development Group (EDRDG), used under CC BY-SA 4.0; the dictionary data we derive from them is likewise available under CC BY-SA. Stroke-order data derives from KanjiVG by Ulrich Apel, used under CC BY-SA 3.0. Pitch-accent data derives from UniDic (NINJAL), used under its BSD licence. Example sentences come from the Tatoeba Project (tatoeba.org), used under CC BY 2.0 FR. Our word-frequency ordering is likewise derived from the Tatoeba Project (CC BY 2.0 FR) and from 青空文庫 / Aozora Bunko public-domain texts, prepared via the globis-university/aozorabunko-clean dataset (CC BY 4.0). JLPT word lists are courtesy of Jonathan Waller (tanos.co.uk). The reading room holds works from 青空文庫 whose copyright has expired. Thank you all ・ apps like this stand on your decades of work.

Your subscription

After the free trial, Shiro is a paid subscription: a yearly plan, price shown before you pay, including any tax. It renews automatically at the end of each period until you cancel, and you can cancel any time ・ it is as easy to cancel as it was to subscribe, and access runs to the end of the period you paid for.

As an EU consumer you have a 14-day right to withdraw from a new subscription. Because the app opens immediately, if you ask to start straight away and then withdraw within those 14 days, we may keep a fair amount for the days you used.

Governing law

These terms are governed by the law of the Czech Republic, and nothing here takes away the consumer rights your own country’s law gives you.

Contact

Questions about any of this? Write to support@kitsune-bi.com ・ we read everything.