Terms of Service

Article 1 (Scope)

These Terms apply to all matters concerning the use of the App between the provider of the App (hereinafter "we," "us," or "the Operator") and users.

The App is provided for users in the countries and regions where we make it available on each app store. We do not warrant that use of the App from any other country or region complies with the laws of that country or region.

Article 2 (Accounts)

Your account in the App is anonymous and is tied to the local storage (localStorage) of this device. If that storage is lost — for example, when the App is uninstalled, the device is reset, or the device storage is cleared — there is no way to restore the same account. Your game history, skill estimate, achievements, and your rating in Versus will all be lost. A feature for carrying an account over to another device is not currently offered.

No account registration is required. The App does not ask you to register your name, email address, phone number, or similar information. Only when you play Versus (rated matches) or the Banzuke Tournament, an identifier (UUID) generated automatically for each device, your display name, and the identifier of the avatar you selected are stored on the server. Your display name is the nickname you set on the Profile screen; if you have not set one, it remains the anonymous display name assigned automatically by the server (for example, "Player#04821"). See the Privacy Policy for details.

Opponents and the rankings display the name you set on the Profile screen (or, if you have not set one, the anonymous display name assigned automatically by the server). Because your display name is visible to other users, do not enter information that identifies you or anyone else, such as a real name, address, phone number or email address. We may change or suspend, without prior notice, a display name that is offensive to other users, infringes the rights of a third party, or is intended to impersonate someone.

During a Versus match, you can report your opponent’s display name. A display name that receives reports from multiple users may be reset, without prior notice, to the anonymous display name assigned automatically by the server.

Article 3 (Age Requirement)

The App is intended for users aged 13 and over. If you are under 13, please do not use the App. Minors should use the App with the consent of a parent or guardian.

We do not collect dates of birth or any other age-related information.

Article 4 (Prohibited Conduct)

When using the App, you must not engage in any of the following conduct:

1. Improperly manipulating game results, ratings, rankings, or achievements, including by altering network traffic, rewriting stored data, submitting false reports to the server, or deliberately arranging wins and losses using multiple accounts (so-called collusion or self-play).
2. Reverse engineering, decompiling, disassembling, or otherwise analyzing or modifying the source code of the App, except to the extent that such acts are expressly permitted by applicable law.
3. Playing Versus or the Banzuke Tournament using bots, scripts, external game engines, or other automated tools, or having any non-human agent play on your behalf.
4. Sending requests to the match server, the server features that return reviews and Ask the Advisor answers, or any other server feature at a frequency far exceeding normal use, or accessing them for the purpose of load testing or penetration testing.
5. Exploiting vulnerabilities in the App, or attempting to circumvent authentication or access controls.
6. Using discriminatory, obscene, or violent expressions, or expressions that infringe the rights of others.
7. Infringing the copyrights, trademarks, or other rights of other users, third parties, or the Operator.
8. Copying, distributing, lending, redistributing, or commercially exploiting all or any part of the App without our permission.
9. Violating laws or public order and morals, or engaging in conduct connected with criminal activity.
10. Any other conduct that we reasonably determine to be inappropriate.

If we determine that you have violated the preceding paragraph, we may, without prior notice, correct your rating, ranking, or match records, suspend your access to Versus and the Banzuke Tournament, or take any other measures we consider necessary.

Article 5 (Provision, Modification, and Suspension of the Service)

We may modify the content of the App, or suspend or terminate its provision, without prior notice.

Within the App, Solo Match and the Edo Journey (games against the on-device AI) work offline. Versus, the Banzuke Tournament, the rankings, post-game reviews, and Ask the Advisor, on the other hand, require a network connection and our servers, and may be unavailable due to maintenance, outages, or network conditions.

The Banzuke Tournament (a knockout event that starts at set times) is not held in rounds where the scheduled time and the number of entrants do not meet the required conditions. We do not guarantee a replacement round when this happens.

Article 6 (Intellectual Property and Trademarks)

All rights in the App and in the programs, images, audio, and text contained in it belong to the Operator or to their respective rightful owners.

The App is based on Reversi, a board game in the public domain played on an 8×8 board in which a player flanks the opponent’s discs to flip them. "Othello" is a registered trademark of another company; we have no capital or partnership relationship with that company and do not use that name in the title, descriptions, or in-app displays of the App. The App is neither endorsed nor supervised by any competitive body or tournament organiser, and no affiliation with them is implied. Names of real historical figures and places, including those of the Edo period, are used as references to recorded history and do not imply any endorsement or affiliation. All depictions, lines, and games of the characters in the App are fiction and not historical fact.

Article 7 (Fees)

Once you have downloaded the App, its game features are available as they are. The App shows advertisements. Alongside that, we sell the following through in-app purchases. The one-time purchases are ad removal, full-body avatars that move and speak, board designs, disc designs, and the jukebox (choosing which of the included tracks to listen to). There is one auto-renewing subscription: Premium (the skill analysis of your record shown as a radar chart, an AI-written summary of it, and Ask the Advisor, which lets you ask the AI for advice during a game). Ad removal is a one-time purchase and is not included in Premium. Items that change how things look change appearance only and have no effect on playing strength or the rules of the game. Post-game reviews can be read without buying any of these products (there is a daily limit on how many you can read). Auto-renewing subscriptions renew automatically at the same price unless you cancel; you can cancel from the settings of each app store. Every one of these products is purchased through the App Store / Google Play on the device where the App is installed. Prices, billing periods, and payment methods are displayed, inclusive of tax, on each app store's product page and on the purchase screen within the App.

Purchase, payment, and cancellation of in-app purchases are handled through each app store’s billing system. We never receive your credit card number or any other payment details.

Without buying anything, you can still play every stage of the Edo Journey, play Solo Match, play Versus and the Banzuke Tournament, view your statistics (except the skill analysis and its written summary), earn achievements, collect red seals, and read post-game reviews (subject to a daily limit). We do not hold the game itself hostage.

Article 8 (Disclaimer)

1. We do not warrant that the App will suit your particular purpose, that it will have the functionality, accuracy, or usefulness you expect, or that it will be free of defects.
2. We are not liable for any damage you incur through use of the App, except where such damage results from our willful misconduct or gross negligence.
3. We are not responsible for recovering game history, settings, or achievements stored on your device that are lost due to device failure, uninstallation of the App, operating system updates, insufficient storage, or any other cause. We do not provide a backup feature for this data.
4. Post-game reviews and Ask the Advisor answers are text produced automatically by a generative AI (Google Gemini), and we do not warrant their accuracy or soundness. Please treat them as reference information only.
5. We are not responsible for the conduct of other users in Versus or the Banzuke Tournament. Disputes between users must be resolved between the parties concerned.
6. Offline operation of the App relies on the content stored on your device. We do not warrant that alternative means will be provided when features requiring a network connection are unavailable.

Article 9 (Handling of Personal Information)

The handling of information in the App is governed by our separately published Privacy Policy. The Privacy Policy forms part of these Terms.

Article 10 (Governing Law and Jurisdiction)

These Terms shall be governed by and construed in accordance with the laws of Japan.

Any dispute arising between the Operator and a user in connection with the App shall be subject to the exclusive jurisdiction of the Japanese court having jurisdiction over the location of the Operator as the court of first instance.

Article 11 (Changes to These Terms)

We may change these Terms when we consider it necessary, without individually notifying users. The revised Terms take effect from the time they are posted on this page.

When we make a material change, we will display the details of the change and its effective date at the top of this page for a certain period. If you use the App after a change, you are deemed to have agreed to the revised Terms.

Article 12 (Contact)

For inquiries about these Terms, please contact us through the channel listed on the Contact page.