Terms of Service

Using the service

Hibi Mondai is a learning tool for practicing Japanese grammar. You may use it to view daily challenges, submit your own sentences, track progress, and review your history. Please use the app for its intended purpose of language practice.

Your account

You are responsible for the account you create and for the activity that happens under it. Please keep your login credentials secure and use an email address you control. Let us know if you believe your account has been accessed without your permission.

Your content

The sentences and answers you submit are your own learner-generated content. You keep ownership of what you write. By submitting content, you allow Hibi Mondai to store and process it so the app can save your history, track progress, and — where applicable — share it with classroom teachers for feedback.

Please do not submit sensitive personal information in your practice sentences, since they are stored and may be processed by the service providers described in our Privacy Policy.

Classroom and teacher features

If you join a classroom, classroom managers such as teachers or admins may be able to view relevant submissions and provide feedback as part of the learning workflow. If you would prefer your practice to stay private, you do not have to join a classroom.

AI教師 (AI feedback)

AI教師 is an optional, user-triggered feature. It is never run automatically — AI feedback is only generated when you choose to request it on one of your own submissions.

• When you request AI教師 feedback, the relevant sentence, grammar point, and your training level may be sent to a third-party AI provider, currently OpenAI, to generate the feedback.
• AI教師 feedback is AI-generated and may be imperfect or incorrect. It is an assistive learning tool, not human review and not an authoritative correction.
• You should use your own judgment, and consult a teacher or authoritative resource when accuracy matters.

Acceptable use

Please do not misuse Hibi Mondai. In particular, do not:

• Submit unlawful, abusive, harassing, or harmful content.
• Attempt to access other users’ accounts or data.
• Interfere with, overload, or attempt to disrupt the service.
• Use the app to violate the rights of others or applicable law.
• Attempt to misuse the AI教師 feature or other features in ways they are not intended for.

Intellectual property

The Hibi Mondai name, branding, app design, and grammar content provided by the app belong to Hibi Mondai. You may use the app for your own personal language practice, but please do not copy, redistribute, or resell the app or its content without permission. As noted above, you keep ownership of the sentences you write.

Service providers

Hibi Mondai relies on third-party providers to operate, including Supabase for authentication, database, and backend storage; Vercel for hosting; Sentry for error monitoring and observability; and, when you request AI教師 feedback, OpenAI to generate that feedback. We may also use email infrastructure and support providers to communicate with you. See the Privacy Policy for more detail on how data is handled.

Beta and availability

Hibi Mondai is currently in early beta and is offered on an “as is” and “as available” basis. We do not guarantee that the service will always be available, error-free, secure, or that any specific feature will be maintained. Features may change, and the app may occasionally be unavailable for maintenance or other reasons.

No learning or academic guarantee

Hibi Mondai is a study aid. We do not guarantee the correctness or completeness of grammar content or AI-generated feedback, and the app is not a substitute for professional instruction, formal assessment, or certified academic guidance. Please do not rely on it as your only source for exam preparation or academic decisions.

Account deletion and termination

You may request deletion of your account and learning data at any time through the account deletion page or by emailing support@hibimondai.app. We may also suspend or end access to accounts that misuse the service or violate these terms.

Account and learning data is retained while your account is active, and AI教師 feedback is kept as part of your learning history. After deletion, some minimal records may be retained where required for legal, security, abuse-prevention, operational, backup, or dispute-resolution reasons, and backup copies may take additional time to expire.

Changes to these terms

These terms may be updated as Hibi Mondai adds features, expands testing, or prepares for broader public availability. Continuing to use the app after an update means you accept the revised terms.

Contact

Questions about these terms or the service can be sent to support@hibimondai.app.

A note on these documents

These are founder-drafted launch documents intended to be clear and practical for an early-beta learning app. They should be reviewed by legal counsel before any broad commercial launch.