Last updated: September 11, 2026
"DiaryMate" (the "App") is provided by an independent individual developer (Shigeharu Miyamoto, the "Developer"). This policy explains what information the App handles and how.
The App has no account or sign-up system. The Developer does not directly collect contact information such as your name, email address, or phone number through the App.
The App handles three kinds of information:
The "fragments" you enter throughout the day, your conversation history with a character, and the finished diary page are stored only on your device (technically, in the device's IndexedDB storage). This data is never sent to or stored on the Developer's servers or any cloud service.
The one exception is when you choose "Make a page", "More", or the daytime "✦ (deepen)": at that moment, your input text and conversation history up to that point are sent temporarily for AI response generation, described in section 2 below. This transmission is not for storing your diary data — it exists solely to generate the AI's response.
Only when you tap "Make a page", "More", or "✦ (deepen)", your input text and conversation history up to that point are sent, via a server function the Developer operates on Vercel, to the AI provider OpenRouter (and the underlying model providers OpenRouter routes to). The content is used solely to generate the in-the-moment AI response (a character's reply or a draft diary passage) and is not stored in any database on the Developer's server.
AI response generation is available only while you have an active paid plan (including the 7-day free trial). If you are using the free plan, conversations with a character and diary drafts are generated entirely through local, on-device processing, and no input is sent externally.
For abuse prevention (rate limiting the number of requests within a time window), the requester's IP address may be held temporarily in the server's memory. This is not a persistent record — it is automatically cleared after a short period and is never written to disk or a database.
This data transmission always originates from your own action (tapping "Make a page", "More", or "✦"); the App never sends this data automatically or continuously. The same notice is available in the App from the ⓘ mark in the bottom bar.
The App's paid features (subscription) are processed through Apple's App Store payment system and RevenueCat (a subscription management service). Payment details (such as credit card numbers) are handled by Apple and are never received directly by the Developer or RevenueCat.
The App uses an anonymous identifier (App User ID) issued by RevenueCat to manage your subscription status (active/inactive). In the App's current implementation, this identifier is not linked to any personally identifying information such as your email address or name.
The App shares information with only the following three parties, each strictly to the extent necessary to provide the feature you triggered:
| Recipient | Information shared | Purpose |
|---|---|---|
| OpenRouter (AI provider) | Input text and conversation history at the moment you choose "Make a page", "More", or "✦ (deepen)" | Generating AI responses (conversation, draft diary text) |
| RevenueCat (subscription management) | Anonymous App User ID, subscription status events | Managing and syncing subscription status |
| Apple (App Store / StoreKit) | All payment information | Payment processing |
The App does not share information with any advertising or analytics company beyond the above. The App does not include any advertising SDK, tracking SDK, or analytics SDK.
The App is not directed at children under 13. The Developer does not knowingly collect personal information from children under 13. If you believe a child under 13 has used the App and provided personal information, please contact us at the address below so we can review and take appropriate action, including deletion.
Because diary data exists only on your device, you can delete it completely at any time through the App's own delete function, or by uninstalling the App. The Developer holds no copy of your diary data, so there is no need to request deletion from the Developer for this data.
For requests regarding your subscription status or anonymous identifier, please contact us using the information below.
If this policy changes, we will announce it through an in-app notice, the App's App Store listing, or by updating the "last updated" date on this document. For significant changes, we will consider providing a more prominent in-app notice.
For questions about this policy or your privacy, please contact: