Terms of Use

Last updated: October 23, 2026

These terms are an agreement between you and Rota Studio (“we”, “us”), the maker of Mainichi. They apply to the Mainichi app, its account and sync service, and this website. When you use Mainichi, you agree to these terms and to our Privacy Policy. If you do not agree, do not use Mainichi.

The app

We license the app to you. We do not sell it. Apple’s Licensed Application End User License Agreement (the Standard EULA) governs your license to use the app, and these terms add to it. If the two conflict about the license of the app, the Standard EULA applies.

Your account

An account is optional: every study feature works without one. If you make an account:

• Use an email address that is yours.
• Keep your password secret. You are responsible for what happens in your account.
• Use one account for one person.
• Be at least 13 years old, or the minimum age in your country.

You can delete your account at any time in the app: Settings → Account → Delete account.

Sync

Sync copies your progress between your devices. We work to keep it available and correct, but we do not promise that it never fails or never loses data. We can change or stop the sync service. If it stops, the app keeps working on your device with the progress that it has.

Purchases

Some features of Mainichi can need a purchase: a subscription or a one-time purchase. Apple sells them through the App Store, and Apple’s terms apply to the payment, the billing and refunds.

• A subscription renews automatically at the end of each period, unless you cancel it at least 24 hours before the period ends.
• Apple charges your Apple Account when you confirm the purchase and at each renewal.
• To cancel, open the subscription settings of your Apple Account. The cancel applies at the end of the period that you paid for.
• Apple handles refunds. We cannot give them.
• Prices can change. Apple tells you before a new price applies to your subscription.

Acceptable use

Do not:

• try to get into the account or the data of another person;
• send automated or excessive requests to our servers, or try to disrupt them;
• use Mainichi to break the law.

We can suspend or close an account that breaks these rules. The progress on your device stays, and the app keeps working without an account.

Content and licenses

The dictionary and kanji data in Mainichi come from third-party sources, under their own licenses. The app lists each source and its license in Settings → About & sources, with the license of the app’s content database. Rota Studio owns the software and the design of the app, and the name Mainichi.

We work to make the content correct, but it can have errors. Mainichi is a study aid: we do not promise a learning result, such as a pass of a test.

No warranty

Mainichi comes “as is” and “as available”. To the full extent that the law allows, we give no warranty of any kind, express or implied, including merchantability, fitness for a particular purpose and non-infringement.

Limit of liability

To the full extent that the law allows, Rota Studio is not liable for indirect, incidental, special, consequential or punitive damages, or for lost data or lost profits. Our total liability for all claims about Mainichi is not more than the greater of: the amount that you paid for Mainichi in the 12 months before the claim, or 50 US dollars.

Changes and termination

We can change these terms. We post the new version on this page and change the date at the top. If you use Mainichi after a change, you agree to the new terms. You can stop the use of Mainichi at any time.

Law

The law of the State of California, USA, governs these terms, without its conflict-of-law rules. The state and federal courts in California decide any dispute about them. These terms do not take away a right that the consumer law of your country gives you, such as a right to go to the courts where you live.

Apple

These terms are between you and Rota Studio, not Apple. Apple is not responsible for Mainichi or its content.

General

• These terms, the Standard EULA and the Privacy Policy are the whole agreement between you and us about Mainichi.
• If a court finds a part of these terms invalid, the other parts stay in effect.
• If we do not enforce a right, we do not give it up.
• We can transfer these terms to a company that takes over Mainichi. You cannot transfer them without our consent.

Contact

Rota Studio · support@mainichi.co