Terms of Service

Article 1 — Scope and agreement

These Terms of Service (the Terms) set out the conditions for using Koyu's architectural planning service, related websites, APIs and connected features (collectively, the Service). The operator of the Service is the person identified in, or disclosed by the method described in, the Specified Commercial Transactions Act Disclosure.

Users may use the Service after agreeing to these Terms when creating an account or on another screen expressly designated by Koyu. Anyone using the Service for a company or other organization represents that they have authority to bind that organization to these Terms. These Terms do not restrict consumer rights that cannot legally be excluded.

Article 2 — Accounts and teams

Users must provide accurate registration information, manage their credentials appropriately and promptly notify Koyu of suspected unauthorized use. Unless otherwise provided by law, users are responsible for activities conducted through their accounts. Accounts must not be shared by multiple people.

Minors may use the Service only with the consent of a parent or other legal representative as required by the laws of their place of residence. Where team features are provided, team administrators manage members, plans and permissions. A member leaving a team or deleting an account does not automatically delete team plans managed by other members.

Article 3 — The Service

Koyu supports the exploration and sharing of architectural plans using site information, design policies and spatial descriptions in muro format. Features may include retrieving site and zoning information, AI generation and revision, derived views such as plans, 3D views and area schedules, diagnostics, saving, history, publishing and export. Available features, generation budgets and other limits are subject to the conditions displayed within the Service or at purchase.

Koyu may change, suspend or discontinue features for quality, security, legal compliance or changes to third-party services. If saved plans would be materially affected, we will provide advance notice or an opportunity to export them where practicable.

Article 4 — Architectural, regulatory and AI limitations

The Service supports exploration and communication at the planning and early concept stages. It does not provide the professional services of architects, structural or building services designers, surveyors or other professionals; legal advice; building confirmation; permits; or certification of legality, safety or buildability.

AI outputs, maps, addresses, zoning, regulatory information, areas, dimensions, diagnostics and exports may contain omissions, delays, bias or errors. An absence of warnings or consistency in a description does not mean a design is lawful, safe or buildable. Before making decisions concerning actual plans, applications, estimates, procurement, construction, evacuation, fire prevention, structures, accessibility or similar matters, users must, at their own responsibility, check the source materials and all outputs and obtain the necessary judgments from qualified professionals and public authorities.

The Service must not be used as the sole basis for decisions affecting people's rights, safety, employment, housing, credit or access to essential services.

Article 5 — User content and processing permission

Users retain the rights they hold in submitted site information, design policies, instructions, messages, muro files, drawings, uploads, evaluations and other information (User Content). Users grant Koyu a non-exclusive license to store, reproduce, transform, transmit and display User Content as necessary to provide, synchronize, generate, revise, display, export, protect and support the Service, and to perform the limited quality and safety evaluation described in the Privacy Policy.

Users warrant that they have the rights and authority necessary to provide User Content to Koyu and the identified processors. Do not submit unnecessary personal information, sensitive personal information, confidential information, third-party trade secrets or materials for which the necessary rights have not been cleared.

Article 6 — Koyu Loop and model training

Ordinary agreement to these Terms and ordinary use of the Service do not constitute consent to contribute User Content to Koyu Loop or permission to train or further train models belonging to Koyu or third parties. If Koyu Loop is launched, we will request a separate, voluntary choice after describing the data, purposes, methods, models, recipients, retention periods and limitations following withdrawal.

Koyu may use aggregated metrics that neither identify nor reproduce individuals or User Content, such as generation times, failure rates, token volumes and diagnostic counts, to improve operations. Generation records may also be used for quality and safety evaluation. In-service evaluation, request processing by AI providers and model training are distinct uses, as explained in the AI & Data Policy.

Article 7 — Outputs and intellectual property

As between users and Koyu, users may use outputs generated for them to the extent permitted by law. However, Koyu does not guarantee that AI-generated outputs qualify for copyright or other rights, are original, differ from outputs generated for third parties or do not infringe third-party rights. Users must conduct the necessary rights research and checks before actual use.

Rights in the Service, software, UI, documents, trademarks, design systems, generation instructions, models and improvements that are not User Content belong to Koyu or their respective rights holders. Open-source software is subject to its respective licenses.

Article 8 — Prohibited conduct

Users must not:

• Violate laws, these Terms or third-party rights
• Submit information they are not authorized to process or disclose
• Misrepresent outputs as approved or guaranteed by professionals, public authorities or Koyu
• Circumvent or interfere with authentication, team separation, generation budgets, billing, rate limits or security controls
• Transmit malware, make excessive automated requests, exploit vulnerabilities or interfere with other users
• Use the Service or its outputs to develop harmful, deceptive, discriminatory or unlawful systems
• Analyze or extract protected parts of the Service beyond what is expressly permitted by law

Article 9 — Third-party services

The Service uses third-party services for authentication, databases, hosting, AI, maps, addresses, regulatory information, payments and other purposes. Necessary information is sent to the relevant provider when users use the applicable features. Major providers and types of information are described in the Privacy Policy. Third-party outages, specification changes or terms may limit Koyu's features.

Article 10 — Fees, automatic renewal, cancellation and refunds

When accepting paid service subscriptions, we display the plan, tax-inclusive price, billing cycle, usage limits, payment methods, availability timing, automatic renewal date and cancellation and refund terms before purchase is finalized. By confirming recurring billing, users authorize the displayed amount to be charged on each renewal date until cancellation.

Users may cancel before the next renewal date using the method described within the Service. Unless otherwise stated at purchase, access continues until the end of the paid period and no prorated refund is provided for mid-period cancellation. Exceptions apply where a refund is required by law, the purchase terms, duplicate billing or a Koyu payment error. Details appear in the Specified Commercial Transactions Act Disclosure and on the purchase screen.

Article 11 — Suspension and termination

Users may stop using the Service and request account deletion from Koyu at any time. Koyu may restrict, suspend or terminate access for material breaches, misuse, security risks, non-payment, legal requirements or a risk of harm to others. Where circumstances permit, we provide advance notice and an opportunity to remedy the issue.

Deletion of a personal team cannot be undone. Shared team plans may remain under the team's control. Retention and deletion details are described in the Privacy Policy.

Article 12 — Disclaimer of warranties

To the extent permitted by law, the Service is provided as is and as available. Koyu does not guarantee uninterrupted operation, preservation of all device-local data, the accuracy, completeness, fitness for a particular purpose or non-infringement of outputs, or compliance with professional or legal requirements. Users must retain the exports and backups needed for their work.

Article 13 — Limitation of liability

These Terms do not exclude Koyu's liability for willful misconduct, gross negligence or other liability that cannot legally be excluded. Otherwise, to the extent permitted by law, Koyu is not liable for indirect, special or consequential damages, lost profits, loss of data or damages arising from reliance on outputs contrary to Article 4.

Where a monetary liability cap is legally permitted, Koyu's aggregate liability relating to the Service is limited to the amount actually paid by the user to Koyu in the 12 months before the event giving rise to liability. This cap does not reduce rights under the Consumer Contract Act or other mandatory laws.

Article 14 — Changes and renewed consent

Koyu may revise these Terms in response to changes in the Service, laws or risks. Each published version has a unique document version and effective date, and previous versions are retained at version-specific URLs. Typographical corrections and other revisions that do not materially change users' rights or obligations may take effect upon notice alone.

For changes to fees, purposes of User Content use, liability, cancellation or other material rights or obligations, we provide necessary advance notice and request explicit renewed consent where continued use alone is considered insufficient. The version requiring consent is managed as an acceptance revision separate from the document version.

Article 15 — Governing law, jurisdiction and contact

These Terms are governed by Japanese law. The Tokyo District Court has exclusive agreed jurisdiction at first instance over disputes relating to the Service, except where mandatory consumer laws allow another court.

Inquiries may be sent to our contact desk.