Terms of Use
Japanese Idioms: YojiKoma · com.roaco.yojijukugo
The app is being prepared for release. These terms govern use of the app after release. Established on 1 October 2026.
1. The app and its operator
ARABEKUTO,K.K. (the “Company”) provides the Android app Japanese Idioms: YojiKoma (com.roaco.yojijukugo) to help users learn Japanese four-character idioms through manga, conversations and quizzes. These terms apply specifically to this app, not to the Company’s other apps.
Address: 4-23-6 Takanawa, Minato-ku, Tokyo 108-0074, Japan. Contact: support@arabect.jp.
2. Learning and intended users
The Japanese version is primarily intended for children in elementary school grades 3–6. The English version is for learners of Japanese, including children and adults. Minors should discuss use with a parent or guardian and obtain the consent required by applicable law for purchases and other relevant actions.
The 325 idioms are a selected collection. We do not guarantee complete coverage of school or exam requirements, improved academic performance or exam results. In English mode, the subject remains Japanese four-character idioms.
3. Free lessons, purchases and restoration
30 idioms are free. One purchase unlocks all 325 idioms, including 295 additional ones. Basic and advanced lessons do not require separate purchases. There are no ads, subscriptions or automatic renewals.
Before confirming a purchase, check the price, currency and payment terms shown by Google Play. The actual price may vary by store country and currency.
Restoring a purchase requires the Google Play account used for the purchase, connectivity and the store’s requirements. It is separate from restoring learning records. A purchase does not promise transfer to another operating system, every future lesson, or indefinite support for every device or OS.
Refunds follow Google Play’s process and applicable law. If a refund, revocation or similar event removes your paid entitlement, access to paid lessons is restricted. In the current app, we do not delete your learning records solely for that reason. Deleting purchase-related information does not automatically issue a refund.
4. Local records and backups
Learning records and settings are stored on your device. There is no separate app login or automatic cloud sync. Device failure, clearing app data or uninstalling can remove your records, so back up important data yourself.
Restoring a manually created encrypted backup replaces your current learning records. Export current records first if you need to keep them. Purchase rights, display language and color theme are not included. We do not store backup passwords and cannot unlock a backup or issue a replacement password.
5. Content rights, prohibited uses and changes
Rights in the app, learning materials, manga and characters belong to the Company or the respective rights holders. Unauthorized copying or redistribution beyond ordinary learning use, fraudulent purchases, infringement, unauthorized access and unlawful use are prohibited. This does not prohibit uses permitted by applicable law.
We may change features or lessons to fix errors, maintain compatibility or improve safety. Changes affecting important purchased functionality or ending its provision will be accompanied by reasonable advance notice and measures required by applicable law.
6. Responsibility and statutory rights
We do not guarantee that learning content or the service is free from errors or interruptions. These terms do not exclude responsibility for intentional misconduct or gross negligence, liability that cannot legally be limited, or mandatory consumer rights that apply where you live.
See the Privacy Policy for information handling. Important changes will be announced on this page and, where appropriate, in the app. The Japanese and English versions describe the same conditions. Please contact us with questions.