Terms of Use
Effective date: September 11, 2026
Last updated: September 11, 2026
These Terms of Use (the "Terms") set out the conditions for using the mobile application "Yomoe Math" (the "App") provided by Yomoe Studio ("we", "us"). You are deemed to have agreed to these Terms at the point you download or use the App. When a child uses the App, a parent or guardian should agree to these Terms on the child's behalf before letting the child use it.
Article 1 (What the App is)
The App is a learning application in which children practise addition, subtraction, multiplication and division. All questions are created on the device. Learning features, including creating questions and practising, are available without a network connection.
Article 2 (Conditions of use)
1. You shall use the App in compliance with these Terms and all applicable laws.
2. The App is designed mainly for children aged 3 to 10. When a child uses the App, a parent or guardian should review and agree to these Terms and the Privacy Policy and keep an eye on the child's use.
3. Purchases, sending feedback, opening external pages and similar operations are to be performed by a parent or guardian, and the App places a parent check before them.
Article 3 (Prohibited conduct)
You shall not do any of the following when using the App.
(1) Copy, modify, disassemble, decompile, or reverse engineer the App
(2) Redistribute, sell, lend, or publicly transmit the App or any part of it
(3) Circumvent or disable the App's ad display or billing features
(4) Place an excessive load on our servers or network, or attempt unauthorized access
(5) Violate laws or public order and morals, or engage in any other conduct we deem inappropriate
Article 4 (Data management and responsibility)
1. Learning progress, records, badges, and settings are stored only on the device. We do not hold or manage them and cannot restore them.
2. We are not responsible for restoring data lost through loss, failure, reset, or replacement of the device, uninstallation of the App, or defects in the OS or the App. There is no feature for transferring learning records to another device.
Article 5 (Advertising)
1. The App displays ads in order to remain available free of charge. Ads are served with child-directed settings and never appear while questions are being answered.
2. Ads are delivered by third-party advertising providers. We do not warrant the accuracy, legality, or safety of ad content, of the goods or services offered by advertisers, or of the destinations that ads link to. Any transaction with an advertiser is between you and that advertiser, and we are not a party to it.
3. The handling of information associated with ad delivery is governed by the Privacy Policy.
Article 6 (In-app purchase)
1. The App offers a paid version (the "Pro version"). The Pro version provides the following.
(1) No ads inside the App (the banner on the home screen and the full-screen ad after a round of questions)
2. Even in the free version, Practice (every course for addition, subtraction, multiplication, division and their combinations), Adventure (every world and level), Daily Challenge, the Review Book, Badges, and the learning records in Parent Mode are all available without restriction. The Pro version does not unlock any of these features or levels.
3. Purchase procedures, billing, and refunds are governed by the terms and practices of the Apple App Store or Google Play. We do not process payments and are not in a position to decide whether a refund is granted. If you wish to request a refund, please follow the procedure of the relevant store.
4. Purchased features can be restored using the same account (Apple ID / Google account) used at the time of purchase. Transfer between different accounts or different platforms is not possible.
5. If the display of your purchase status is lost due to device loss or data erasure, please use the restore purchase feature inside the App.
Article 7 (Changes, suspension, and termination of the service)
1. We may change the content of the App, add or remove features, and suspend or terminate its provision.
2. The preceding paragraph includes changes to how features are divided between the free version and the Pro version (including changes to the scope of features available in the free version). We do not guarantee that the scope of the free version's features, or its availability free of charge, will be maintained in the future.
3. For changes that materially affect users, we will give notice by posting within the App or by another appropriate method, a reasonable period before the change takes effect. This does not apply in cases of emergency maintenance, security necessity, or legal requirement.
4. Notwithstanding the preceding three paragraphs, for users who have already purchased the Pro version, we will not make the features provided at the time of purchase paid features again, nor will we restrict them.
5. We are not liable for damages arising to users from changes under this Article, except where paragraph 4 is breached.
Article 8 (Intellectual property)
Copyright, trademark rights, and other intellectual property rights relating to the App belong to us or to the rightful holders. These Terms grant you a non-exclusive right to use the App within the scope of these Terms and do not transfer any intellectual property rights.
Article 9 (Disclaimer of warranties and limitation of liability)
1. The App is provided "as is". We make no warranty of any kind, express or implied, as to its completeness, accuracy, usefulness, fitness for a particular purpose (including achieving any particular learning outcome), or freedom from interruption or error.
2. We are not liable for damages arising to you from use of, or inability to use, the App, except where we have acted with intent or gross negligence.
3. Even where we are liable, the amount of compensation is limited to the amount you have paid to us in relation to the App.
4. This Article does not apply to the extent it would be invalid under the Consumer Contract Act or other mandatory law.
Article 10 (Changes to these Terms)
We may change these Terms where we deem it necessary. The changed Terms take effect when posted within the App or on the app store, and if you use the App after the change you are deemed to have agreed to the changed Terms.
Article 11 (Language)
1. The Japanese version of these Terms is the authoritative text.
2. We may provide translations into English and other languages for convenience. Translations are provided for reference only, and in the event of any discrepancy or difference in interpretation between the Japanese version and a translation, the Japanese version prevails.
3. The preceding two paragraphs apply equally to the Privacy Policy and other documents we provide in relation to the App.
Article 12 (Governing law and jurisdiction)
These Terms are governed by the laws of Japan. In the event of a dispute between us and a user in relation to the App, the Tokyo District Court shall be the exclusive court of first instance by agreement.
Article 13 (Contact)
For inquiries about these Terms, please contact us at:
Yomoe Studio
contact@yomoestudio.com