Scope
These Terms apply to every matter that arises between the operator and users in connection with the Service. That includes simply browsing without creating an account.
Notices the operator publishes separately within the Service — what is shown on the plans page, the notes attached to individual experiences, the guidance on the contact form — form part of these Terms. Where such a notice and these Terms differ, the specific notice takes precedence.
How personal information is handled is set out in the privacy policy rather than here.
What the Service is
The Service opens exploration experiences in the browser, bringing a 3D model, an explanation, checkpoints, and a discovery log together into one piece. The subjects range across science, technology, and history, but the aim is always the same: to let you work a mechanism with your own hands and see how it holds together.
Official experience content is built after consulting published sources. Even so, it is a form of expression made for exploration and discovery — it grants no qualification or certification, and it is not a substitute for professional advice. For decisions involving medical, legal, financial, or safety matters, please consult a suitably qualified professional.
The Service promises no particular outcome. How far you travel, and what you carry back, is left to your own exploring.
System requirements
A browser with WebGL support is required for the 3D views. Depending on your device and browser settings, 3D may not render at all, or may render in a simplified form.
Some experiences load models of several tens of megabytes. Please keep this in mind if you are on a metered connection.
Providing a device, a browser, and a network connection — and the cost of doing so — is your responsibility.
Accounts
Some experiences can be tried without an account. Keeping a record of your discoveries, and using a paid plan, require registration.
You can register with an email address and password, by linking a Google or X account, or with a passkey. Two-step verification (TOTP) can be enabled if you want it.
You agree to keep your registration details accurate and current, and to manage your credentials — passwords, passkeys, and the rest — at your own responsibility. Accounts may not be lent, shared, transferred, or sold to anyone else.
If you become aware of unauthorized use by someone else, please change your credentials and contact the operator promptly. Actions taken through your account before you reach us may be treated as your own.
Use by minors
If you are a minor, please use the Service with the consent of a parent or guardian. The same applies to signing up for a paid plan.
We ask parents and guardians to help manage the account so that they can see how it is used and what is being paid for.
Fees and plans (Dawn / Stella / Astra)
Dawn is free to use. Stella and Astra are paid plans; they differ in how much of the catalog opens up and in how discovery logs are kept. Prices and billing intervals (monthly / yearly) are shown on the plans page, and all displayed prices include tax.
Payment, cancellation, changes to payment methods, and payment history are handled through Stripe Checkout and the Stripe Customer Portal. Card details are handled by Stripe and are never stored on the operator’s servers.
Unless you cancel, a paid plan renews automatically at the billing interval you chose. You can cancel at any time, and after cancelling you keep the features you have unlocked until the end of the billing period you have already paid for.
Fees already paid are non-refundable except where required by law. If you change plans partway through a billing period, the difference is adjusted according to Stripe’s calculation.
Prices, the shape of the plans, and which experiences each plan opens may change. Where a change works against you — a price increase, for instance — we will announce it within the Service beforehand and apply it from your next renewal.
Discovery logs and what you write
Rights to what you enter into the Service — exploration logs, checkpoint answers, notes on how something felt, and your own memos (together, your “discovery log”) — remain yours.
The operator stores, processes, and displays your discovery log only as far as is needed to run the Service, to show you where to pick up again, and to investigate faults.
On Dawn, discovery logs are kept inside the browser you are using. They do not carry over if you clear your browser data or open the Service on another device. On Stella and above, they are synced to the cloud against your account.
Please do not enter another person’s personal or confidential information without a proper basis for doing so. What you enter remains your responsibility.
About the accuracy of the content
Official experience content is checked against published sources and published with those sources cited. Even so, errors and passages that have fallen out of date may remain.
The 3D models are built so that the mechanism can be read at a glance. Scale, proportion, color, and the speed of motion are in places different from the real thing for the sake of legibility. They cannot be relied on as a basis for real-world design or measurement.
If you spot something that reads wrong, please tell us through the contact form. We will check it and correct it.
Prohibited conduct
So that this stays a place anyone can explore in safety, please refrain from the following.
- Acts that violate laws or public order and morals.
- Acts that infringe the rights, property, reputation, or privacy of others.
- Impersonating another person, or registering false information.
- Interfering with the operation of the Service, or with other people’s exploration.
- Unauthorized access, probing for vulnerabilities, reverse engineering, or otherwise improperly analyzing or abusing how the Service works.
- Excessive automated access, mechanical harvesting of content, or circumventing usage limits and safety measures.
- Reproducing, reposting, redistributing, or building into another product any official experience content — including 3D models, text, and images — without the rights holder’s permission.
- Lending, sharing, transferring, or selling an account to anyone else.
If you find a security problem
If you find a security problem in the Service, please contact us through the contact form before exploiting or publishing it. Steps to reproduce the issue help us confirm it quickly.
The minimum checking needed to make such a report will not be treated as “probing for vulnerabilities” under the section above. Reaching into other people’s data, applying load that would take the Service down, and retaining or publishing anything you obtain all fall outside that allowance.
Limits and suspension
To keep the Service running steadily and to prevent misuse, we may place limits on how often and how much it can be accessed.
Where we judge that these Terms have been breached, or where safety leaves us no alternative, we may restrict features, suspend an account, or delete it, without prior notice.
We will explain the reason as far as we reasonably can. If none of it sounds like you, or you believe we have judged wrongly, please get in touch through the contact form.
Deleting your account
You can delete your account at any time. If you are on a paid plan, please cancel it before deleting the account.
When an account is deleted, discovery logs synced to the cloud are deleted or anonymized within a reasonable period, except where a law requires them to be kept. Deletion cannot be undone.
Intellectual property
Rights to the Service and to official experience content — including 3D models, text, images, audio, and code — belong to the operator or to the rightful rights holders.
You may view all of it within the scope of your own private exploration. Anything beyond that — screening it publicly, redistributing it, using it commercially — requires permission in advance.
External material and images cited inside an experience each have their own rights holder and conditions. To use them beyond the extent shown in the citation, please check with the rights holder concerned.
Sharing part of a screen or a link to an experience, with the source made clear, in order to write about it or recommend it, is welcome.
Disclaimer
The Service is provided on an “as is” basis. The operator does not warrant the completeness, accuracy, usefulness, or fitness for a particular purpose of the content, nor that the Service will be available without interruption.
To the extent permitted by law, the operator is not liable for damages arising from your use of the Service. This does not apply where the damage is caused by the operator’s intent or gross negligence.
Even where the operator is liable under applicable law, that liability extends only to damages that would ordinarily arise, and for users on a paid plan it is capped at the amount actually paid over the twelve months preceding the damage.
The same applies to damages arising from causes beyond the operator’s reasonable control, such as natural disasters, network failures, or outages at external services.
Changes, interruptions, and closure
The operator may add, change, or discontinue features and experiences in order to make the Service better. What is published may be rotated over time.
All or part of the Service may be suspended temporarily for maintenance, to deal with a fault, or for reasons on the side of an external service. Where a suspension is planned in advance, we will announce it as far ahead as we can.
If the Service is to close entirely, we will give reasonable notice. For anyone on a paid plan at that point, we will set out how the remaining billing period is handled, in line with applicable law.
Changes to these Terms
The operator may revise these Terms as laws change or the Service changes.
Revised Terms take effect once posted within the Service. Where a significant revision works against you, we will post it and also give reasonable notice ahead of the date it takes effect.
By using the Service after a revision, you agree to the revised Terms.
Governing law and disputes
These Terms are governed by and interpreted in accordance with the laws of Japan.
If any part of these Terms is held invalid or unenforceable, the remainder stays in effect.
If a dispute arises in connection with the Service, we will first aim to resolve it through discussion. Failing that, the Tokyo District Court shall be the court of exclusive jurisdiction for the first instance.
Contact
For questions about these Terms, reports of something written wrongly, or requests for permission, please write to us through the contact form.