Terms of Service

Last Updated: August 16, 2026

Introduction and Acceptance

Welcome to Sokuji ("Service"), a real-time AI-powered translation application provided by Kizuna AI Lab ("Company," "we," "our," or "us"). These Terms of Service ("Terms") govern your access to and use of our browser extension, desktop application, and related services.

By downloading, installing, accessing, or using Sokuji, you agree to be bound by these Terms. If you do not agree to these Terms, please do not use the Service.

Definitions

  • "Service" refers to the Sokuji application, including the browser extension, desktop application, and all related features.
  • "User," "you," or "your" refers to any individual or entity that accesses or uses the Service.
  • "Balance" refers to the prepaid balance, denominated in United States dollars (USD), that is purchased from Kizuna AI Lab and used to access Kizuna AI-provided translation services.
  • "Third-Party API Key" refers to API credentials obtained directly from third-party AI service providers (such as OpenAI, Google, Palabra AI) by the User.
  • "Kizuna AI Service" refers to AI translation services provided through Kizuna AI Lab's infrastructure that are charged against your Balance.

Service Description

Sokuji provides real-time AI-powered translation services through two usage modes:

Free Usage Mode (Third-Party API Keys)

  • Users can connect their own API keys from supported AI providers (OpenAI, Google Gemini, Palabra AI, etc.)
  • No charges from Kizuna AI Lab; users are billed directly by their chosen AI provider
  • Users are responsible for managing their API key security and usage limits

Prepaid Balance Usage Mode (Kizuna AI Service)

  • Users purchase a prepaid Balance, denominated in United States dollars (USD), from Kizuna AI Lab
  • Your Balance is charged when using Kizuna AI-provided translation services
  • Translation is charged by actual usage as measured by the AI provider, and the amount depends on the provider you select
  • Estimated hourly rates are shown on your wallet page; because charging follows actual usage, the amount is normally lower

Account Registration

You must be at least 13 years old to use the Service. If you are under 18, you represent that you have your parent or guardian's permission to use the Service. By using the Service, you represent and warrant that you meet this age requirement.

To access certain features, including Balance-based services, you must create an account. You agree to:

  • Provide accurate, current, and complete information during registration
  • Maintain the security of your account credentials
  • Promptly update any information to keep it accurate and current
  • Accept responsibility for all activities that occur under your account

You are responsible for maintaining the confidentiality of your account password and for restricting access to your account. You must notify us immediately of any unauthorized use of your account.

Accounts that remain inactive for 24 consecutive months (no login or service usage) may be subject to closure. We will send a notification at least 30 days before closing an inactive account. Any remaining Balance in inactive accounts will be forfeited upon account closure.

Notifications and Communications

We may send you notices through the following methods: (a) in-app notifications within Sokuji; (b) email to the address associated with your account; (c) posting notices on our website. You are responsible for keeping your email address current.

By creating an account, you consent to receive important service-related communications from us via these methods.

Balance and Payment

Balance Purchase

  • Balance can be purchased through the application using supported payment methods
  • All prices are displayed in the applicable currency at the time of purchase
  • Balance is non-transferable between accounts
  • Balance added by a top-up is valid for one (1) year from the date of the top-up that created it

All prices displayed are inclusive of applicable consumption tax (Japan) or value-added tax. For purchases made outside Japan, local taxes may apply according to your jurisdiction.

We will send a reminder notification at least 30 days before your Balance expires. Expired Balance will be automatically forfeited and cannot be recovered, refunded, or extended. It is your responsibility to use your Balance before it expires.

We may add promotional Balance to your account free of charge, for example a trial credit when you verify your email address. Promotional Balance is valid for the period stated when it is granted — seven (7) days for the email-verification trial credit — and is used before purchased Balance. The 30-day reminder above does not apply to promotional Balance: the grant notice is the only reminder. Promotional Balance is not refundable or transferable and is forfeited on expiry.

Balance Consumption

Translation is charged by actual usage as measured by the AI service used, so the amount depends on the provider and model. Estimated hourly rates are shown on your wallet page, and because charging follows actual usage the amount is normally lower than the estimate. Your Balance is updated once the provider reports the usage, shortly after a session ends, rather than continuously during the session.

Refund Policy

  • Unused Balance: Refund requests for unused Balance may be submitted within 14 days of purchase. A processing fee may apply.
  • Consumed Balance: Balance that has been consumed is non-refundable.
  • Service Issues: If Balance was consumed due to technical issues as solely determined by Kizuna AI Lab, we may credit the affected amount back to your account, subject to the following conditions: (a) the issue must be reported within 30 days of occurrence; (b) the total credits per account shall not exceed 20% of the Balance purchased in that calendar year; (c) Kizuna AI Lab reserves the sole right to determine what constitutes a technical issue and whether a credit is warranted.
  • Refund Process: Contact support@kizuna.ai with your purchase details and reason for refund.

Free Services (Third-Party API Keys)

When using your own API keys from third-party providers:

  • You are solely responsible for obtaining and managing your API keys
  • You must comply with the terms of service of each third-party provider
  • You are responsible for all charges incurred from third-party providers
  • API keys are stored locally on your device and are never transmitted to our servers

We make no warranties regarding the availability, quality, or performance of third-party AI services. Any issues with third-party services should be directed to the respective provider.

Acceptable Use

Permitted Use

  • Personal real-time translation
  • Business communication translation
  • Educational purposes
  • Accessibility support

Prohibited Activities

  • Use the Service for any illegal or unauthorized purpose
  • Attempt to reverse engineer, decompile, or disassemble the Service
  • Interfere with or disrupt the Service or servers
  • Use the Service to transmit harmful, offensive, or illegal content
  • Resell, sublicense, or commercialize access to the Service without authorization
  • Circumvent any security measures or access restrictions
  • Use automated systems or bots to access the Service beyond normal usage
  • Violate any applicable laws or regulations

Intellectual Property

The Service, including all software, content, features, and functionality, is owned by Kizuna AI Lab and is protected by international copyright, trademark, and other intellectual property laws.

Subject to these Terms, we grant you a limited, non-exclusive, non-transferable, revocable license to use the Service for personal or internal business purposes.

You retain ownership of any content you provide through the Service. Audio and translation content are processed in real-time and are not stored by us.

Disclaimers

Service Provided "AS IS"

  • Implied warranties of merchantability or fitness for a particular purpose
  • Accuracy, reliability, or completeness of translations
  • Uninterrupted or error-free operation
  • Freedom from viruses or other harmful components

AI-powered translations may contain errors. Users should not rely solely on translations for critical communications, legal documents, medical information, or safety-critical applications.

We do not guarantee that the Service will be available at all times. The Service may be subject to limitations, delays, and other problems inherent in the use of internet and electronic communications.

Limitation of Liability

  • Kizuna AI Lab shall not be liable for any indirect, incidental, special, consequential, or punitive damages
  • Our total liability shall not exceed the amount you paid for Balance in the twelve (12) months preceding the claim
  • We are not liable for any loss resulting from unauthorized access to your account
  • We are not liable for any issues arising from third-party AI services

Indemnification

You agree to indemnify and hold harmless Kizuna AI Lab, its officers, directors, employees, and agents from any claims, damages, losses, liabilities, and expenses (including attorneys' fees) arising from your use of the Service, your violation of these Terms, your violation of any rights of third parties, or your use of third-party API keys.

Termination

Termination by You

  • You may stop using the Service and delete your account at any time
  • Any unused Balance may be forfeited (subject to refund policy)
  • Your right to access the Service will immediately cease

Termination by Us

  • We may suspend or terminate your access if you violate these Terms
  • We may terminate if your use poses a security risk
  • We may terminate if required to do so by law
  • We may terminate if we discontinue the Service

If we discontinue the Service entirely, we will provide at least 30 days advance notice. In such case, users with unused Balance may request a pro-rata refund for Balance purchased within the 12 months preceding the discontinuation, subject to a processing fee. Refund requests must be submitted within 60 days of the discontinuation notice.

Changes to Terms

We may modify these Terms at any time. We will notify you of material changes by posting the updated Terms on this page, updating the "Last Updated" date, and sending an in-app notification or email for significant changes. Continued use of the Service after changes constitutes acceptance of the modified Terms.

Governing Law and Dispute Resolution

Before initiating formal legal proceedings, both parties agree to first attempt to resolve any dispute through good-faith negotiation. The complaining party shall send written notice describing the dispute to the other party. Both parties shall then have 60 days to attempt informal resolution. If the dispute cannot be resolved informally within this period, either party may proceed with formal legal action as described below.

These Terms shall be governed by and construed in accordance with the laws of Japan, without regard to its conflict of law provisions.

Any disputes arising out of or relating to these Terms or the Service shall be subject to the exclusive jurisdiction of the courts of Tokyo, Japan.

In the event of any discrepancy between the English and Japanese versions of these Terms, the Japanese version shall prevail for users in Japan.

General Provisions

These Terms, together with our Privacy Policy, constitute the entire agreement between you and Kizuna AI Lab regarding the Service.

If any provision of these Terms is found to be unenforceable, the remaining provisions will continue in full force and effect.

Our failure to enforce any right or provision of these Terms will not be considered a waiver of those rights.

Force Majeure: Kizuna AI Lab shall not be liable for any failure or delay in performing its obligations under these Terms due to circumstances beyond its reasonable control, including but not limited to natural disasters, war, terrorism, riots, pandemics, government actions, power failures, internet or telecommunications failures, or failures of third-party service providers.

Contact Information

If you have any questions about these Terms, please contact us:

Legal: legal@kizuna.ai

Support: support@kizuna.ai

GitHub: github.com/kizuna-ai-lab/sokuji