Privacy Policy

1. Operator

Yuichi Tanaka (an individual)
Contact: latlon.design@gmail.com
We will provide our address without delay if you request it at the contact above.

2. Information stored on your device

The following information is stored on your device. Backup when signed in, and sending for readings, are as described in section 3.

• Date of birth, time of birth, place of birth (latitude and longitude, and place name)
  * Used for the fortune calculations. Not sent to any external AI.
• The nickname you set (what Yomi calls you)
• Calendar events (the app reads and writes the calendar on your device)
  * Only if you allow it in Settings, just the titles and times of events (for the morning reading, that day’s events; when you ask Yomi a question, the next 7 days — 14 days for a Deep read) are sent as described in 3-1. By default they are not sent.
• Photos (read in order to show the photos you took that day over the calendar. The images and the places they were taken do not leave your device. Only the number of photos and the number of places you went are handled as described in section 4)
• The line you write at night, and your evening answers
  * Only if you allow it in Settings, these are sent as described in 3-1. By default they are not sent (except that, when you ask for a month-end look back, the number of days is sent as described in 3-1).
• What Yomi remembers (the text you typed when asking, and the gist of Yomi’s reply at the time)
  * Sent each time you ask a question, as described in 3-1. You can erase it with “Have her forget everything” in My page.
• The Apple account identifier obtained through Sign in with Apple (we do not ask for your name or email address)

Your stardust balance and your record of tips (including the wishes written on plaques) are backed up to your own iCloud (iCloud Key-Value Store) so that they are not lost when you change devices. This is stored inside your Apple account, and we cannot read it.

2-1. How the information is used

The information described in sections 2 and 3 is used for the following.

• Calculating fortunes, and creating the text of readings, answers to your questions, and books
• Saving your records and restoring them with the same account
• Processing purchases, restoring what you bought, and responding to inquiries and feedback
• Managing limits against overuse, and detecting and preventing fraudulent use
• Investigating problems and improving the app (summaries of usage and crashes; 3-3)
• Delivering notices (notifications, and news from the operator)
• Posting plaques on the shared plaque wall (only if you hang one; 3-6)
• Sending TestFlight invitations (only if you entered your address on the waitlist; 7)

We do not use it to show advertising. We do not sell your information. If we change how it is used, we will let you know as described in section 10.

3. Information sent outside your device

The app communicates with the following services. No advertising, and no external analytics or crash-collection tools (SDKs), are built in. Only summaries of usage and crashes are recorded, by our own means, on our relay server (3-3).

We do not give your information to anyone other than those listed here. We do not sell it, and we do not give it out for advertising. However, when disclosure is required under law, we may comply to that extent.

3-1. What is sent to OpenAI and Google for readings and questions

We send the results of the fortune calculations in order to turn them into readable text. We send them only after first showing you what will be sent and obtaining your consent. Until you consent, and while Settings → “Use AI for readings” is off, nothing is sent (your reading is delivered as fixed text).

The AI that writes the text changes between your early use and afterwards. The morning reading (today’s card), the Deep read of a day, answers to your questions, and your very first reading are written by Google’s Gemini for roughly your first 30 times, and by OpenAI after that. When Gemini fails to produce one, OpenAI writes it on the spot. While Gemini is switched off, OpenAI writes as well.

The count is kept per device, counting the times Gemini wrote. Even if you have been using the app before, Gemini writes roughly the first 30 times after you update to the version that introduced this. When you reinstall the app, or after you delete your account, the count starts over.

Preparatory work — the month-end look back, the interviewer for the book questions, looking things up, telling what kind of question you asked, and so on — is handled by OpenAI from the start. For that reason, during your early use, the same question text is sent to both OpenAI and Google. Whichever it is sent to, the kinds of material are the same, as follows.

• The planetary placements calculated from your birth chart (the signs of the Sun, Moon, Ascendant and so on, houses, aspects) and your life path. How far an angle is off is rounded to three levels — “nearly exact / close / loose” — before sending
• Whether your birthday is near (“this week is your birthday week,” “your birth month,” and the like. The day itself is not sent)
• The state of the sky that day, the date, and the flow of the hours
• The nickname you set — sent so the reading can address you
• The “on your mind,” “hobbies” and “what you want to come true” you set, your MBTI, and the questions you answered at the start (where you are now, the day that matters, your words)
• Only if allowed in Settings: the titles and times of that day’s events
• Only if allowed in Settings: the line you wrote at night and your evening answers (for the morning reading, the most recent 3 days; for the month-end look back, up to 10 days of that month)
• Only if allowed in Settings: your patterns (how your evening answers relate to that day’s weather, air pressure, number of events and number of photos)
• When you ask for a month-end look back, the number of days you answered that month, and the numbers of days that matched and did not match (numbers only)
• For people registered as “people on your mind”: their name (the nickname you gave them), their relationship to you, and their signs, and the placements of your compatibility with them (rounded) — sent in order to read about that person. Their date of birth, time of birth and place of birth are not sent (the signs and placements are calculated inside the device). The consent screen in the app shows this in the same way
• The text of the question you typed on the question screen, and the past questions Yomi remembers (the very text you typed at the time — up to 600 characters each — and the gist of Yomi’s reply. Up to 20 items. You can erase them with “Have her forget everything” in My page). If your question contains a date written as a birthday (for example, “he was born on May 3, 1995”), that date is masked before sending, and is also masked when remembered. Compatibility is calculated inside the device, and only the result (where you fit easily, where some care is needed) is sent
• Short words describing the weather — when you ask a question, the weather for the next 7 days (14 days for a Deep read; e.g. sunny, rain); for a Deep read, the current temperature and how it feels (e.g. 31 degrees, muggy). The location itself is not sent
• The full text of the questions and answers in the questions for The Written Book (to create the interviewer’s text)
• In the questions for The Written Book and in a Deep read of a question, only the names and types of companies, schools, places and the like that came up (to look up publicly available information on the web. Names of people, and the reason for your question, are not sent. You can stop this with Settings → “Look up names you mention”). The results of the lookup (including the publicly listed names of a company’s officers and their publicly listed dates of birth) are sent as material for the reading

What is not sent: email address, Apple identifier, device identifier, advertising identifier, the date of birth, time of birth and place of birth of you or the people you registered, where you are now (neither coordinates, nor direction or distance from there), photos, contacts.

Because no identifier is sent along, what is sent is not linked to your account or device on OpenAI’s or Google’s side. However, your nickname is sent as it is. Also, from the combination of your sign and “birthday week,” the approximate time of your birthday can be inferred. We state this for the sake of accuracy.

To OpenAI, we send with the setting that tells OpenAI not to store the response on its side (store: false). Even so, how long it is retained on OpenAI’s side depends on OpenAI’s policies (linked in 3-2). When sending to Google (Gemini), this setting is not attached (Gemini’s endpoint has no equivalent setting). How what is sent is handled on Google’s side, and how long it remains, depends on Google’s policies and the Gemini API terms (linked in 3-2).

On whether what is sent is used to train AI, each company publishes the following (as we checked on October 13, 2026).

• OpenAI: Content sent through the developer interface (API) is not used to train or improve models unless the developer opts in. As a record for monitoring abuse, the content sent and the responses may be kept for up to 30 days (possibly longer where required by law, for example). We have not opted in to allow use for training
• Google (Gemini): We use the Gemini API as a paid service. Under Google’s terms, content sent and responses under the paid service are not used to improve Google’s products. To detect and prevent use that violates the terms, and for disclosures required by law, the content sent and the responses are logged for a limited period only (the number of days is not stated in the terms)

Both are what each company publishes; we have not verified the inside of either company. If a company changes its handling, we will revise this section.

The “people on your mind” entries and event titles contain information about people other than yourself. Because those people have no opportunity to consent to the app themselves, information that could identify them, such as date of birth, is not sent; only the signs needed for the reading are calculated on the device and sent. Even so, their name (the name you gave them) is sent in order to read about and answer about that person.

Event titles, too, may contain the names of people other than yourself. For that reason, neither event titles nor the line you write at night is sent by default. We ask you once, on the day a record is first made, and the app is built not to send until you allow it. After allowing, you can switch it at any time from Settings → “Readings.”

A line judged to contain words concerning a threat to life is automatically excluded from the material for readings and is not sent outside (as a record it is yours, so it stays on your device).

3-1-2. What is sent to Google (Gemini) when writing a book

What is sent to Google for readings and questions is as described in 3-1 (roughly your first 30 times). This section is about books.

The Written Book and the free Rough draft are written by Google’s Gemini. For a book, only when you buy The Written Book and answer the questions, and when the Rough draft (the one Yomi writes once 7 days of records have built up / “Have just the first half written” on the shelf) is written, the following is sent via our relay server (on the premise that you have given the consent described in 3-1). Because the Rough draft has no questions, what is sent is the planetary placements and the timing of their cycles, the names of the “people on your mind” who appear in the book, and, if allowed in Settings, a summary of your records.

• The full text of the questions and answers in the book questions, and the key points drawn from them (including quotations of your words, and numbers, company names and people’s names that came up)
• The planetary placements calculated from your birth chart (the planets’ signs, houses, aspects and so on), and the timing of the planetary cycles ahead (ranges of years and months)
• Only if allowed in Settings: a summary of the most recent 30 days of records (the line you wrote at night, how the day felt, your evening answers, what Yomi said that day, and the numbers of days that matched and did not)
• The names of the “people on your mind” who appear in the book
• The key points of the results of looking up public information (the lookup results in 3-1)

What is not sent when writing a book: your nickname (the way the book addresses you is inserted inside the device), email address, Apple identifier, device identifier, the date of birth, time of birth and place of birth of you or the people you registered, your age as a number, photos, contacts. For readings and questions, as described in 3-1, your nickname is also sent to Google so that you can be addressed.

However, if you write your name, your workplace or the like in your answers to the book questions, it is sent as written. Also, from the timing of planetary cycles (for example, “the year Saturn returns to where it was when you were born”), your approximate year of birth can be inferred. We state this for the sake of accuracy.

For a book, only when the text could not be created with Google, the same content may be re-sent to OpenAI to create the text. Readings and questions work the same way: when one could not be created with Google, the same content is re-sent to OpenAI, and OpenAI writes it on the spot.

When we have Google (Gemini) write the text of a book, too, it is sent under the paid service, as described at the end of 3-1.

3-2. Provision to third parties in foreign countries

The app uses the services of the following companies outside Japan. All of them are companies in the United States of America.

Of these, sending to OpenAI and Google in order to create text is done, as described in 3-1, only after showing you on the app’s screen what is sent and where (OpenAI and Google in the United States) and obtaining your consent. You can withdraw consent at any time in Settings → “Use AI for readings.” A backup of your records is placed with Google (Firebase) only if you yourself use Sign in with Apple.

The system for protecting personal information in the United States

This is an outline based on the survey published by Japan’s Personal Information Protection Commission (information as of October 2021).

• At the federal (nationwide) level, the United States has no comprehensive personal information protection law that applies to all private businesses. What exists are laws for individual sectors, such as communications, finance and healthcare, and laws of individual states (the content differs by state)
• The United States participates in the APEC (Asia-Pacific Economic Cooperation) Cross-Border Privacy Rules (CBPR) system
• The United States is not included among the countries and regions that the Personal Information Protection Commission recognizes as “having a system of protection at the same level as Japan” (the countries of the EU, and the United Kingdom)
• For that reason, the right to request disclosure, correction or suspension of use of your own information, in the same form as under Japanese law, is not always recognized under United States law. Also, under United States laws and regulations, public bodies such as investigative authorities may require businesses to disclose information

For details, see the pages of the Personal Information Protection Commission (in Japanese): Foreign systems (United States of America) / Legal systems of other countries and regions. Systems may change. Requests to us (disclosure, correction, suspension of use, erasure) are accepted by us as described in section 5, whichever company the information is placed with.

Measures each company takes to protect information

This is what each company publishes (checked on October 13, 2026).

• OpenAI: Content sent through the API is not used to train models unless the developer opts in. Records for monitoring abuse are kept for up to 30 days (except where required by law, for example). We send with the setting that tells OpenAI not to store the response on its side (3-1). How API data is handled · Privacy policy
• Google (Gemini API): We use it as a paid service. Content sent and responses under the paid service are not used to improve Google’s products. To detect and prevent use that violates the terms, and for disclosures required by law, they are logged for a limited period only. Google handles them in accordance with the arrangement under which it processes information on our behalf (the data processing addendum). Content sent may be stored temporarily in countries where Google has facilities. Gemini API Additional Terms of Service
• Google (Firebase): Google handles information in the position of processing it on our behalf. It is encrypted both in transit and at rest. Its information security management has undergone third-party certification and assessment (ISO 27001; SOC 1, 2 and 3). The sign-in system (Firebase Authentication) runs in data centers in the United States. Privacy and Security in Firebase · Google Privacy Policy
• Cloudflare: The platform that runs our relay server and where its records are kept. What we place there and do not place there, and the period until erasure, are decided by us as described in sections 3 and 3-4 (the text of fortune requests is not placed there). Privacy policy · Materials on security and legal compliance (Trust Hub)
• Apple: Weather & Privacy · Apple Privacy Policy

The measures taken on our side are as described in section 6. On top of that, the app is built so that date of birth, time of birth and place of birth are not sent to any external AI, and no identifier is attached to what is sent to AI (3-1).

3-3. Records of usage and crashes (our relay server)

To improve the app, summaries of how it is used and of crashes are recorded on our relay server. No external analytics service is used.

• What is recorded: four events — the app was opened, today’s card was turned, a feature was used for the first time, a review request was shown — and summaries of crashes and freezes (only numbers indicating where in which program it stopped). Also, the result of each request to AI for a reading (whether it succeeded, the type of failure, time taken, amount used, character count of the material sent), and the results of lookups (number looked up, number found, the reason when not found) — numbers and fixed terms only, with no text and none of the names looked up
• What is sent along: the device identifier (the random value in section 3), a number for each session, the app version, the iOS version, the device model, language, time zone, the date you first opened the app and the number of days since, and whether you have taken The moon vow. The country is determined by the relay server from the connection (the IP address is not stored)
• What is not sent: text you wrote, your questions, birth information, events, photos, location, fortune text, or that day’s fortune score (because it is a value determined from birth information, it is no longer sent as of the October 2026 version). Character types are filtered mechanically, so Japanese text is dropped at the first character
• How to stop it: Turning off Settings → “Share usage” stops the sending, and anything not yet sent is erased as well. At that time the device identifier is also newly re-created. You can also re-create it with “Make a new identifier” on the same screen
• Fortune requests carry the same identifier regardless of this setting, for managing limits (the relay server entry in section 3)

3-4. Records that remain on our server, and for how long

Records on the relay server (Cloudflare) are automatically erased, or have their identifier removed, once the following periods have passed.

3-5. Feedback

Text you send from “Feedback” in My page is kept in Google’s Cloud Firestore, and only we read it. Kept together with it are the email address you wrote for a reply (optional), the app version, device model, iOS version, language, the date and time sent, and, when “Share usage” is on, the device identifier. No account identifier is attached.

The text you send is kept for up to 1 year and then erased automatically. Because no account identifier is attached, it is not erased along with your account when you delete the account. If you would like it erased before 1 year has passed, please contact us at the contact in section 1.

3-6. The shared plaque wall

Only if you hang a plaque written after a tip on the shared plaque wall, the text of the wish, your sign, the item, the purchase record signed by Apple and the device identifier are sent to our relay server.

• What other users can see is only the serial number, the sign, the item, the text of the wish, and the day it was hung. No names or identifiers are shown. The time is rounded to the day
• To check whether it may be posted, the text of the wish is sent to OpenAI’s screening (moderation). Wishes that appear to contain contact details or an address, and wishes that did not pass screening, are visible only to the person who wrote them
• You can report, from the plaque itself, a plaque you want hidden. The operator may also take one down
• 30 days after the hanging period ends, the text of the wish and the device identifier are erased from the server. The serial number, the item, the sign and the purchase’s transaction number remain, so that the same purchase cannot be used to hang a plaque twice

4. Device permissions

All of these can be changed at any time from the iPhone’s Settings.

5. Storage and deletion

• The app’s data is, as a rule, inside your device. If you delete the app, the data on the device is erased with it.
• What Yomi remembers can be erased at any time with “Have her forget everything” in My page.
• The on-device cache of public-information lookup results is erased when it expires, when you turn off “Look up names you mention” in Settings, or when you delete your account.
• The iCloud backup of your stardust balance and record of tips remains even if you delete your account (so that you do not lose what you bought). However, the text of wishes written on plaques is erased when the account is deleted. Deleting the app’s data from the iPhone’s “Settings → Apple ID → iCloud” erases it.
• Even if you sign out, the records on this device remain.
• If you are signed in, “Delete account” inside the app deletes the Firebase backup and the authentication account, and also revokes the Sign in with Apple connection.
• “Delete account” inside the app, whether or not you are signed in, erases the records on our relay server that are tied to this device’s identifier (usage records, records of usage events, the notification destination, the copy of the stardust ledger, plaque wishes, and the per-device records for limits against overuse), and also erases the text of plaque wishes in iCloud. If communication failed, it is re-sent the next time you open the app. If it could not be confirmed from this device that it is you, they cannot be erased and will disappear after the periods in 3-4 (in that case we will tell you on the app’s screen).
• What remains on the relay server even after you delete your account is only: the record of a device whose use was stopped (a measure against fraudulent use), a plaque’s serial number and the purchase’s transaction number (the wish and the identifier are erased), the amount and date and time of stardust delivered, the amount used for each purchase of The Written Book and the number of devices that used that purchase (the transaction number and an irreversible digest; 3-4), and that day’s usage amount per origin (erased after 2 days). Also, records from before an identifier was re-created that could not be erased disappear after the periods in 3-4.
• If you delete while not signed in, the deletion does not reach the Firebase backup. To erase the backup, please sign in with the same Apple account and then delete.
• Text sent through “Feedback” is not erased by deleting the account, and is erased automatically up to 1 year after it was sent (3-5).
• Payment for The moon vow does not stop even if you delete your account. Please cancel it from the iPhone’s “Settings” → your name → “Subscriptions.”
• How long each company retains what was sent to OpenAI and Google depends on each company’s policies (linked in 3-2).

If you wish to have your own information disclosed, corrected, suspended from use, erased, or no longer provided to third parties, please contact us at the contact in section 1. If you tell us “Your stardust number” shown in Settings, we can find which records on the relay server belong to your device.

• Confirming it is you: Please tell us “Your stardust number” shown in Settings, and we will respond regarding the records under that number. If you do not know the number, please say so. We will discuss with you how to confirm.
• Fees: None.
• Complaints: Accepted at the same contact.

6. Measures taken for security management

• The relay server accepts requests only from the genuine app on a genuine device (signature verification by Apple’s App Attest). API keys are not placed in the app; only the relay server holds them.
• All communication is encrypted (HTTPS).
• The records of people who signed in are kept in Firebase under rules that, from the app, let only the owner of that account read and write them (the operator can view them from the administration console).
• The relay server does not store the text of fortune requests, and its operating records (logs) do not contain text, IP addresses or complete identifiers. A retention period is set for each record, and they are erased automatically (3-4).
• Only the operator’s account can read the records.

• The operator is one person, and only that one person handles the records.
• If information is leaked, lost or the like, and a report or notification is required by law, we will report to the Personal Information Protection Commission and notify the persons concerned.
• Information is handled using the services of companies in the United States (Cloudflare, OpenAI, Google). The system in the United States is as described in 3-2.

7. Email addresses entrusted to us on this site (the TestFlight waitlist)

This section is about this website, not the app. Only if you enter your email address on the TestFlight waitlist page (in Japanese), we keep that address. If you do not enter it, we keep nothing.

• Its only use is to send you an invitation to TestFlight (the test version). It is not used to send news or promotions.
• The invitation email arrives from Apple’s TestFlight system (Apple Inc., United States). For that purpose, the address you entered is registered with Apple as a tester. It is not given to any other third party.
• To prevent automated sign-ups, when you submit, Cloudflare Turnstile (Cloudflare, Inc., United States) checks whether the action is by a human. At that time, browser and connection information (including the IP address) is sent to Cloudflare. Your email address is not sent for this check.
• What is recorded along with it is only three things: the date and time received, which link you came from, and the country code. The IP address is not stored.
• It is kept in a database at Cloudflare (Cloudflare, Inc., United States). Because this constitutes provision to a third party in a foreign country, we keep it on the same basis as 3-2.
• 30 days after the invitation is sent, it is erased automatically, record and all. Addresses to which we have not been able to send an invitation are also erased automatically, record and all, 1 year after you entered them (if you are still interested, please enter it again). If you would like it erased sooner, or if an address that is not yours was registered, please contact us at the contact in section 1. We will erase it right away.

8. Use by children

The app is not a service directed at children. People under 18 may not use it. If we learn that we hold information of a person under 18, we will erase it. For in-app purchases, you can use the purchase restrictions in the iPhone’s Screen Time.

9. The nature of the fortunes

What the app tells you is a guide calculated from the positions of celestial bodies, and reading material based on it. It is not a substitute for medical, legal, financial or other professional advice. If you have concerns about your health or state of mind, please consult a professional service.

10. Changes to this policy

If the content changes, we will update this page and revise the date of last update. When there is an important change, we will also let you know inside the app.