Koehiyori Terms of Use

Last updated: October 7, 2026

These terms govern Koehiyori, provided by Roamcraft (the operator). Please read and agree to these terms before using the service.

1. Service and eligibility

Koehiyori is a Japanese-language app that delivers morning and evening text and synthesized voice letters from Hiyori, an AI character, based on your profile and optional diary. It is not a real-time conversation service. You must be 18 or older, sign in and consent to the AI processing described in our Privacy Policy.

Keep your account secure. Do not lend, transfer or misuse accounts. You are responsible for internet and data charges.

We limit the service to adults aged 18 or older to comply with the age requirements of Google Gemini API, which generates the letter text. See the Gemini API age requirements.

2. AI text and speech

Hiyori is not a real person. Text is generated using Google Gemini API and speech using ElevenLabs. Output may contain errors, inappropriate wording or repetition. We do not guarantee accuracy or any particular outcome. The service does not provide medical care, diagnosis, treatment, counseling or emergency assistance.

Delivery times are approximate. Connectivity, outages or external providers may delay or prevent generation or notifications. Not every diary entry or detail will appear in a letter.

3. Trial and subscription

• A seven-day trial of all features starts when your first letter is delivered. The trial does not automatically become a paid subscription. Repeated trials are restricted.
• To receive new letters after the trial, purchase the monthly plan at JPY 980 including tax in Japan. Review the price and terms on the purchase screen.
• The paid plan renews automatically each month until canceled. Purchases and renewals are billed through Apple App Store or Google Play.
• Cancel through the subscriptions settings of the store where you purchased, before the next renewal. Allow at least 24 hours before renewal to complete the process. Exact renewal timing and conditions are shown by the store.
• Deleting the app or account or withdrawing AI consent does not cancel your subscription.
• You can generally continue to use the service until the paid period ends after cancellation. After the trial or paid period ends, new letters and memories stop being generated; delivered letters remain.

Refunds follow the applicable store procedures and policies and applicable law. Your statutory rights remain unaffected. See our Legal Notice for details.

4. Your content and intellectual property

You retain your rights in the diary entries and other content you submit. We process this content as needed to provide the service, including generation, storage and delivery of letters, memories and audio. Rights in the software, characters, images and voice materials belong to the operator or their respective rights holders.

Do not submit or share content that infringes others' rights, redistribute service materials without authorization or misrepresent Hiyori's voice as that of a real person. Uses permitted by law are not restricted.

5. Prohibited conduct

• Illegal activity, infringement of others' rights or privacy, harassment or unauthorized access
• Interfering with the service or circumventing safety measures, usage limits or payment
• Impersonation, account abuse or fraudulent repeated trials
• Inputs or analysis intended to bypass the service's or its providers' safeguards

6. Deletion and consent withdrawal

Deleting an entry removes associated memories but does not rewrite previous letters. The Privacy Policy explains deletion of letters, audio and accounts, and retained records. Withdrawing consent stops AI processing and prevents app use, but does not automatically delete stored data.

7. Changes, suspension and closure

We may suspend service for maintenance, outages or safety, and restrict use as necessary for violations of these terms. Except in emergencies, we will announce material feature changes, price changes or service closure and their timing in advance through the app or this site, including arrangements for paid periods and stored data.

8. Responsibility

We do not guarantee an error-free service or compatibility with every environment. Where damage is attributable to us, we are responsible in accordance with applicable law. These terms do not limit rights under Japan's Consumer Contract Act or other mandatory consumer protection laws.

9. Changes to terms and governing law

We will announce changes and their effective date in advance through the app or site and obtain consent where legally required. These terms are governed by Japanese law. Jurisdiction is determined by applicable law.

10. Contact

Roamcraft
[email protected]