Koezu Terms of Use

Version 2026-11-12 · Effective 12 November 2026

These terms are an agreement between you and the sole-proprietor operator of Koezu in Kyoto, Japan ("we"), who makes and provides Koezu. Koezu is independent of Kyoto University of Advanced Science and the NISAR Laboratory. By creating an account or using Koezu, you agree to these terms and to how we handle data as described in the Privacy Policy.

1. Your account

• You must be 13 or older. If you are under 18, you need a parent's or guardian's consent to buy a plan.
• Give accurate details and keep your sign-in secure. An account is for one person. Don't share it, or sell or pass on invitations.
• We may require an invitation to create an account.
• If you use Koezu for an organisation, you confirm you may act for it. Where a quote, invoice or agreement with an institution differs from these terms, that document applies.

2. Your content

• Your decks, recordings, comments and other content are yours.
• You give us only the permission needed to store, process and transmit them to provide Koezu, for example when you share a deck, or make an AI or voice request.
• You are responsible for having the rights to what you put in Koezu, including other people's voices, images and words.
• You are also responsible for who you send links to. Anyone with a link can open it within that link's settings. Protections such as watermarks and download limits are deterrents: they can't stop screenshots or photos of a screen.
• Comments belong to the people who wrote them. The owner of a deck can delete comments on it.
• We can't read shared decks. If we receive a credible report that a shared link carries unlawful content, we may disable that link.

3. Acceptable use

Don't use Koezu to:

• break the law or infringe others' rights;
• put harmful code in live blocks or shared decks;
• harass people;
• impersonate anyone, or make synthetic voices that mislead people into thinking a real person said something;
• send spam;
• attack, overload or probe Koezu or its users.

4. Koezu's software

We grant you a personal, non-exclusive, non-transferable, revocable licence to use Koezu while your account is active. Koezu's code, design and documentation remain ours.

Except as allowed by law that cannot be excluded by agreement, you may not:

• copy, modify or make derivative works of Koezu;
• decompile, disassemble, deobfuscate or otherwise reverse engineer it, or try to obtain its source code;
• extract its code or assets by automated means;
• remove copyright or other notices;
• use Koezu to build a competing product;
• get around any security or access control.

If you send us feedback, we may use it freely.

5. Plans and payment

• Plans. Koezu has a Free plan, paid plans and add-ons. What each includes, and its price with tax, is shown on the plans page. What applies to you is what was shown when you bought.
• Trial. New accounts get a Pro trial with no card. It ends by itself and never turns into a paid plan.
• Renewal. Monthly and annual plans renew automatically for the same period, at the same price, until you cancel.
• Cancelling. Cancel at any time under "契約の管理" (Manage plan) on the plans page. You keep your plan until the end of the period you paid for, with no further charges.
• Passes and add-ons. These are one-time purchases that don't renew. Koezu AI credits and premium-voice add-ons expire 6 months after purchase. Expired or unused amounts are not refunded.
• Refunds. An annual plan is fully refunded if you ask within 14 days of your first purchase. Charges caused by our error, such as a duplicate charge, are refunded. Other purchases are not refunded, except where the law requires it.
• Price changes. We tell you at least 30 days before a new price applies to your renewal, so you can cancel first.
• Failed payments. If a payment fails, your plan continues for 7 days, and then you move to Free.
• When a plan ends. Your work stays yours. You can still open, edit and export it as PowerPoint, PDF or HTML. Only the paid features stop.
• Purchases from outside Japan are sold by Sold through Link, LLC (Stripe) as the seller. Its terms cover the payment and refunds for that purchase. We provide Koezu itself.
• Institutions may pay by invoice, by the due date shown on the invoice.

6. AI and voice

• AI and voice providers you connect with your own key are governed by their own terms and charges. We are not responsible for their services.
• Koezu AI, translation and premium voice count against your plan's allowances.
• AI output can be wrong. Check it before you rely on it, especially equations, code and translations.
• AI voices. Label them where your audience would otherwise be misled, or where the law requires it.

7. Availability and changes to Koezu

• We work to keep Koezu available and your data safe. We can't promise it will never be interrupted, and features may change.
• If we stop offering a paid service, we will give at least 30 days' notice and refund the unused part of any prepaid period.
• Decks on your own device are your responsibility. Keep your own copies of important work.

8. Suspension and closing

• You may stop using Koezu at any time and ask us to delete your account.
• We may suspend or close an account that seriously or repeatedly breaks these terms, or where the law requires it. We will tell you why, unless the law prevents us.
• If we close a paid account when you haven't broken these terms, we refund the unused part of your plan.

9. Liability

• If we cause you damage intentionally or through gross negligence, we are liable as the law provides.
• If we cause you damage through other negligence on our part (not intentional or gross), our liability is limited to direct and ordinary damage. It is capped at the greater of the amount you paid us in the 12 months before the damage, or ¥10,000.
• Nothing in these terms limits liability that the law, including Japan's Consumer Contract Act, does not allow to be limited.

10. Changes to these terms

• We may change these terms under Article 548-4 of Japan's Civil Code. That applies when a change is in users' general interest, or is reasonable, for example to reflect new features, changes in the law, or security needs.
• We post the new terms and their effective date before they take effect. For changes that reduce your rights, we give at least 14 days' notice in the app or by email, and the app may ask you to confirm.
• If you don't agree to a change, you may cancel before it takes effect.

11. Law and courts

• These terms are governed by the laws of Japan.
• The Kyoto District Court has exclusive jurisdiction in the first instance, except where the law gives exclusive jurisdiction to another court.
• If you are a consumer living outside Japan, you keep the protection of the mandatory laws of your country.

12. Contact

support@koezu.com