Terms of service

Last updated 17 August 2026 · plain English, kept short on purpose

What this service is

Nihongo Sensei is an independent, AI-assisted tool for studying Japanese: daily reviews, lessons, writing practice and a tutor you can talk to. It is free of charge while in early access. Creating an account or using the service means you accept these terms.

Your account

An account is for one person; keep your password to yourself. If you are a minor, use the service with the consent of a parent or guardian. You can stop using the service at any time and ask us to delete your account (see the privacy policy). We may suspend or close an account that breaks these terms, and — because this is a free preview — we may change or discontinue features, or the service itself, without notice.

Acceptable use

Use the service for your own study. Do not attack or overload it, probe other people's accounts, scrape or bulk-download its content or data, or use the tutor to produce unlawful or harmful material. This rule protects the service's availability; it does not limit any rights the third-party licences named in the footer grant you — data covered by those licences is available from its original sources under their own terms.

Your content

What you write or say to the tutor stays yours. So the service can work, you give us a non-exclusive licence to store and process it — including sending it to our AI provider to generate replies — solely to operate the service for you. It is deleted with your account.

AI-generated content

Lessons are produced with AI assistance and human review, and the tutor's replies are generated live by an AI model. Both can be wrong — about grammar, about facts, about anything. If an answer matters, double-check it against a source you trust.

No warranty

The service is provided as-is, with no warranty of any kind: no promise that it is error-free, always available, or that studying here leads to any particular result. We are not liable for damages arising from your use of the service, except where the damage is caused by our intent or gross negligence, or where liability cannot be excluded under the Consumer Contract Act or other applicable law. Nothing on this page is legal advice.

Third-party marks and materials

Nihongo Sensei is an independent study service. It is not affiliated with, endorsed by, or connected to any examination body or textbook publisher.

“JLPT” and 日本語能力試験 are trademarks of the Japan Foundation and Japan Educational Exchanges and Services (JEES). They are named here only to describe which examination levels our N5–N1 study levels are designed to be compatible with; nothing on this site is issued, reviewed or approved by those organisations.

The dictionary and stroke-order data the course is built on have their own owners and licences; their attributions appear in the footer of every page.

Governing law

These terms are governed by the laws of Japan.

Changes and contact

If these terms change, we will announce the change and its effective date on the dashboard before it takes effect, and the date above will change with it. Questions: mainichigo.courses@gmail.com.