Privacy Policy

1. Summary

• The App displays ads. Ads are delivered by Google (AdMob), which obtains an advertising identifier.
• We ourselves do not collect information for advertising. All we receive is the aggregated number of ad impressions and the revenue.
• No account registration is required. We do not collect your name, email address, phone number or date of birth.
• We do not have servers. Your match records and progress are saved only on your device, and match records are not stored on any server.
• While running, the App does not send information to generative AI (there is no mechanism that sends your input or the records on your device to a generative AI service). No analytics tool, and no crash reporting tool that sends data externally, is built into the App itself.
• The App’s introduction page and column (websites) use Google Analytics to understand how they are used. No analytics whatsoever is performed in the App itself (Section 11).
• The App does not request access to location (GPS), contacts, photos, the camera or the microphone.

2. Information Stored Only on Your Device

The following information is saved in the storage area on your device (localStorage). It is never sent outside your device, including to us.

Display settings (jkk.prefs.v1)

Color theme, text size, whether sound effects and music are on and their volume, whether haptic feedback is on, reduced motion, display language, and the mahjong rules chosen.

Ad status (jkk.ads.v1)

The total number of matches finished, the number of matches finished since the last full-screen ad, and the time the last full-screen ad was shown. Used to space out full-screen ads so that they are not shown back to back.

March and growth progress (jkk.progress.v1)

The amounts of provisions, copper and gifts you hold; your rank; bonds; the conquest status of strongholds; the stratagems you have learned; tutorial progress; records of each match (start and end times, the general, adjutant and stratagem chosen, the opponents at the table, damage to walls, and the numbers of wins, deal-ins and riichi declarations, among others); monthly results; records of rewards already granted (so that the same reward is not received twice); the history of lines shown (so that the same line is not repeated in the same scene); a random seed created at installation (to decide, for each device, how lines and the daily orders are chosen); the date the App was first launched and the number and times of launches; observed values of the device clock (so that daily counts cannot be reset by turning the clock back); the number of copper exchanges and rewarded ad views that day; the count used to space out full-screen ads (the number of matches finished since the last full-screen ad and the time it was last shown); the Yaku Book (the number of wins for each yaku and the time each was first won); the Roster (for each opponent, the time of your first match, the number of matches, the number of times you finished above them, and the number of wins you made off them); progress counts toward orders and titles (daily, weekly and all-time); the table cloth and tile back colors you obtained and the ones in use; the titles unlocked and the title worn; story progress (the wall stage reached and the times scenes were viewed); personal bests and history (highest winning hand, greatest wall damage, the numbers of hands and deal-ins in the most recent match, total matches and wins, and so on); the result and time of the match just finished; and on-device statistics (to understand play trends: app launches, the time the App was open (seconds), matches started, finished and quit partway, why a match was quit partway (whether “Quit” was chosen on screen or the App closed during the previous match), match length (seconds) and number of hands, whether a match that ended partway was resumed and, if not, why, failures to save the in-progress record of a match, the results of loading and showing full-screen ads (whether an ad loaded, whether it was shown, and why it was not shown), the seconds from a result to the next match, achievements such as Yaku Book entries and orders, and similar events, recorded only as times, types and values (seconds, numbers of hands, reasons), up to 2,000 entries). On-device statistics are not sent outside your device. Only if you export them from the Settings screen can you choose to send them to us yourself.

In-progress match record (jkk.match.v1)

A record that lets a match resume from where it left off at the next launch if the App closes during the match. It stores how the match was set up (random seed, table number, the character and play style for each seat, special rules and stratagems), every move made so far in that match (each seat’s discards, calls, wins and so on), a check value for the latest position, the time it was saved, the versions of the App and of the rules, and the number of resume attempts. It is deleted when you finish the match and return to camp, quit partway, or choose not to resume.

Store country (jkk.storefront.v1)

The country code of the store (App Store or Google Play) you got the App from, and the time it was checked. Used to decide the default mahjong rules. The country code is read on your device from each Store’s system and is not sent outside your device.

Mahjong rules choice record (jkk.ruleset.choice.v1)

If you choose the mahjong rules on the Settings screen, a record of that choice is saved. Used to notice that the choice was lost when an older version of the App was installed, and to return to the default.

Launch screen record (jkk.splash.v1)

A record of how long to show the launch screen. It contains no information about you.

Store review request record (jkk.storeReview.v1)

The number of times the App was opened, the number and times of requests to show the OS rating screen, and the type of event that triggered each request. Used to avoid asking too often. Whether the rating screen is shown and what it contains depend on each Store’s system (Apple or Google).

Error reports (jkk.crash.v1)

When the App terminates abnormally, the time, where it occurred, a summary of the error, the screen being shown, and the device and version are saved, up to the latest 5. This lets you check the content yourself when you contact us about a problem.

Audio recovery method (jkk.audioRecovery.v1)

The method chosen for restoring sound on iOS after returning from another app. Saved only if you change it from “Error reports” on the Settings screen.

The names in parentheses are the names used in the storage area on your device (localStorage). All of them begin with “jkk.” and are deleted together by “Delete all saved data” in the App. Automated checks confirm that this list does not leave out any name actually used.

Your matches, progress and settings in the App are all saved in the storage area on your device (localStorage). We do not have servers. If that storage area is lost, for example because the App is deleted, the device is reset or the device storage is cleared, there is no way to restore your progress. We do not currently offer a way to transfer data between devices.

3. Ads

The App shows full-screen ads, at certain intervals, when you return from a match result screen (whether you won or lost) to camp (home) or go straight on to the next match, and rewarded ads that you choose to watch yourself on the merchant screen (after watching one to the end, you receive the in-game resource “provisions”). No ads are shown during a match. Watching rewarded ads is optional, and you can keep playing without watching them. Rewards are granted on your device, and nothing about them is sent to our servers.

Ads are delivered using Google AdMob. To show ads, prevent invalid clicks and measure effectiveness, Google obtains the following information.

• Advertising identifiers (the advertising ID on Android and the IDFA on iOS). These are identifiers assigned to each device, and you can reset or delete them yourself at any time. They are not linked to your name or email address.
• Your approximate location, estimated from your IP address. This is not a street address or coordinates, but a unit coarser than a city.
• Technical information such as the device model, OS version, language and screen size.
• The number of times ads were shown, whether they were clicked, and whether rewarded ads were watched to the end.

Google obtains and uses this information as an ad network, and we do not receive it. All we receive is the aggregated number of impressions and the revenue. For how Google handles it, please see “How Google uses information from sites or apps that use our services” (https://policies.google.com/technologies/partner-sites).

On iOS, when the App is first launched (if you have not yet made a choice), it shows a screen asking for permission to track (Apple’s App Tracking Transparency). Only if you allow tracking may Google use the advertising identifier (IDFA) and combine it with your activity in other companies’ apps and websites to show ads tailored to your interests. If you do not allow it, ads are still shown, but they are not tailored to your interests, and the App’s features do not change. On Android, the advertising ID settings of your device apply.

You can switch to ads that are not tailored to your interests as follows.

Delete the advertising ID on Android

You can delete or reset the advertising ID from the device’s “Settings” → “Google” → “Ads”. Once it is deleted, ads will not be tailored to your interests (ads themselves will still be shown).

Do not allow tracking on iOS

Choose “Ask App Not to Track” when the App asks for permission to track, or change it from the device’s “Settings” → “Privacy & Security” → “Tracking”. If you do not allow tracking, ads are still shown, but they are not tailored to your interests.

In regions where consent is required, such as the European Economic Area (EEA) and the United Kingdom, Google’s consent screen is shown at launch so that you can choose whether ads tailored to your interests may be shown. You can change your choice at any time from the Settings screen.

4. Purposes of Use

• Running matches and deciding their outcomes, and recording and displaying progress
• Keeping the display, sound and control settings you choose
• Showing ads and granting the rewards of rewarded ads
• Investigating problems (only when you check the records on your device yourself and attach them to an inquiry)
• Understanding and improving play trends (only when you export the on-device statistics from the Settings screen and send them to us yourself)

We do not use information for any purpose other than the above. We do not use the records or settings on your device for ad delivery or for analyzing your interests and preferences, and we do not pass them to ad networks.

5. Information We Do Not Collect

The App does not obtain any of the following information. This is not merely a statement of policy; it means that these functions do not exist in the implementation. The information that Google obtains for ads is described separately in Section 3 (it is not included here because it is not obtained by us).

• Analytics or activity tracking in the App itself (Google Analytics, Firebase Analytics or any other analytics tool). Measurement on the introduction page and the column (websites) is described separately in Section 11 (it does not extend to the App itself). The App does have a mechanism that counts play trends only on your device (the on-device statistics in “March and growth progress” in Section 2), but it never sends them outside your device, including to us.
• Crash reporting or error collection tools that send data externally (such as Firebase Crashlytics or Sentry). The App does have a mechanism that keeps a summary of abnormal terminations only on your device (“Error reports” in Section 2), but it never sends it outside your device, including to us.
• Name, email address, phone number, address, date of birth and gender.
• Precise location from GPS, contacts, calendars, photos, the camera, the microphone and health information.
• Credit card numbers or other payment information (the App has no purchase feature).
• Browsing history and the use of other apps.

6. Provision to Third Parties

We do not provide the information we obtain to third parties, except as required by laws and regulations. We never sell the information we obtain.

The only external business the App communicates with is Google (AdMob). Separately, the introduction page and the column (websites) send data to Google Analytics. In both cases, the servers may be located outside Japan.

Google (AdMob, ad delivery)

Used to deliver ads in the App. Google is not our contractor; it obtains and uses advertising identifiers and other information as an independent ad network. What is obtained and how to limit it are described in Section 3.

Google LLC (Google Analytics, introduction page and column only)

Used to understand how the introduction page (https://jankokushi.aicreonext.com/) and the column (articles under https://jankokushi.aicreonext.com/column/) are used. Nothing is sent from the App itself. What is sent and how to stop it are described in Section 11.

When providing personal data to a third party in a foreign country, we provide on this page, in accordance with the Act on the Protection of Personal Information, the name of the destination country and information on that country’s system for the protection of personal information. If you would like more detailed information, please contact our contact point.

7. Retention Periods

Data on your device

Kept until you delete it or the storage area on your device is lost. Only the latest 5 error reports are kept; older ones are discarded automatically.

Data on servers

We do not have servers, so we store no data.

Measurement data for the introduction page and the column

Stored in Google Analytics. The retention period for data linked to individual page views is set to 14 months, after which such data is deleted automatically (aggregated figures remain; Section 11).

8. How to Delete Data

You can delete the data saved on your device yourself at any time.

1. Open the “Settings” screen of the App.
2. Press “Delete all saved data”. To prevent mistakes, the data is deleted when you press it once more to confirm.

Deleting the App also deletes the data on your device. You can change how Google handles the information it obtains for ads using the methods in Section 3.

9. Security Measures

• The App has no servers of ours and does not send your records outside your device.
• Communication with ad networks uses encrypted connections.
• Our policy is not to output authentication or other secret information to logs, and this is ensured by automated checks.

10. Use by Minors

The App is intended for users aged 13 and over. Because we do not collect information about age, we cannot verify users’ ages. Parents and guardians, please check your children’s use as appropriate.

11. About Analytics (Introduction Page and Column Only)

To understand how the App’s introduction page (https://jankokushi.aicreonext.com/) and column (articles under https://jankokushi.aicreonext.com/column/) are used, we use Google Analytics, provided by Google LLC. Only the introduction page and the column are covered; no analytics whatsoever is performed in the App itself.

Recipient

Google LLC (Google Analytics). Measurement data may be sent to Google servers including www.google.com, in addition to the Google Analytics measurement servers. Its servers are located in the United States. Storage for advertising purposes (the ad_storage cookie setting) is always disabled in every region.

Information sent

The URL of the page viewed and the referrer (which page you came from), the type of device and browser, the screen size, the language setting, an approximate region estimated from your IP address (the IP address itself is not stored), an identifier stored in a cookie (a code that does not identify you personally), the fact that a button on the page was pressed (which link led to the store page; for the column, whether the link was partway through or at the end of an article), the fact that you pressed a link in the "Related apps" section at the end of a page that leads to one of our other games or to our company website (including the destination of the link and where you pressed it: at the end of the introduction page or of a column page), the type of page viewed (introduction page or column), and the date and time of viewing and the time spent.

Purposes of use

Improving the introduction page and the column, and understanding which links lead to the store pages. The information is not used for any purpose other than these 2.

If you do not want to be measured, you can stop it in any of the following ways.

• Visits from the European Economic Area (EEA), the United Kingdom and Switzerland are not measured unless consent is given. Because we do not show a request for consent (a consent banner), no measurement takes place in these regions. Whether a visit comes from these regions is determined from the time zone and language settings of your browser. If this cannot be determined, no measurement takes place.
• If “Do Not Track” or Global Privacy Control is enabled in your browser, no measurement takes place.
• You can stop measurement by installing the opt-out browser add-on provided by Google (https://tools.google.com/dlpage/gaoptout).
• For how Google handles information, please see Google’s Privacy Policy (https://policies.google.com/privacy).

12. Changes to This Policy

We may change this Policy in response to changes in laws or the addition of features. The revised content applies from the time it is posted on this page. If we make a change that substantially expands the types of information collected or the purposes of use, we will notify you in the App in advance.

13. Contact

For inquiries about this Policy and the handling of information, please contact us at the following.

Operator

合同会社AICREO NEXT

Email address

contact@aicreonext.com