Privacy Policy
This is a translation of the Japanese original. The Japanese version is authoritative. If there is any discrepancy between the two, the Japanese version prevails.
IMUSTERA ("we") respects the privacy of users of the following apps (together, "the App") and handles information appropriately.
Apps covered
- Japanese Folktale Gamebook
This page explains what information the App handles, and what it does not.
1. Introduction
The App is provided by IMUSTERA, a sole proprietorship.
The App is a gamebook in which you read through Japanese folktales and choose options that change how the story unfolds.
We do not collect any personal information such as names or email addresses. The App has no text entry fields of any kind.
2. Information we collect
2-1. Usage statistics
The App uses Firebase Analytics, a service provided by Google, to collect statistics about how the App is used. We use this to find problems and to improve the App.
The following is collected:
- The first time the App was opened
- When use of the App began and ended
- How long the App was in use
- When the App was updated or removed
- Device information (model name, OS version, screen size, language setting, country or region)
- The version of the App
- App Instance ID
The App Instance ID is a number created automatically when the App is installed. It is not linked to any name or contact information. If you delete the App and install it again, a different number is created.
We do not collect which screens you viewed or which stories you read within the App. This is technically known as screen view logging (screen_view), and the App does not use it.
This information is held on Google's services. For how Google handles information, please see Google's privacy policy.
2-2. Information stored on your device
The App stores the following information only on your device:
- Story progress (how far you have read, the results of the choices you made, which characters joined you)
- Settings (language, and whether you chose text mode or voice mode)
- A record of whether the instructions have been shown
This information is never sent outside your device. We cannot see it either.
If you delete the App, this information is removed from your device as well.
3. Microphone and speech recognition
The App has a voice mode, in which you choose options by speaking and the story is read aloud.
We ask for permission to use the microphone only when you use voice mode. The microphone is not used in text mode.
When you choose an option by speaking, the App uses the speech recognition built into your device's operating system (iOS). Through this operating system feature, audio data may be sent to Apple. This is not sent by the App; it is how the device's speech recognition works. For how Apple handles information, please see Apple's privacy policy.
The App itself does not record or store audio. Recognised words are used on the spot, only to select an option.
The App uses the speech synthesis built into your device to read the story aloud. This is processed entirely on the device and is not sent anywhere.
4. Information we do not collect
The App does not collect any of the following:
- Personal information such as names, email addresses, telephone numbers, or postal addresses
- Location data
- Contacts
- Photos or camera data
- Advertising identifiers (IDFA)
The App does not display advertisements, and does not collect information for advertising purposes.
5. How we use information
We use the statistics described in Section 2 only for the following purposes:
- To find and fix problems
- To understand how the App is used, and to improve readability and ease of use
- To decide which devices and OS versions to support
We do not use it to identify individual users, and we do not attempt to identify individuals from the statistics.
6. Sharing with third parties
We do not sell or provide the information we collect to third parties.
However, because we use the services of the following two companies, those companies receive information as part of how those services work:
- Google (usage statistics via Firebase Analytics)
- Apple (audio data when the speech recognition feature is used)
No information is passed to any other company or service.
7. Use by children under 13
The App is based on Japanese folktales and is made so that children can read it.
Children under 13 should use the App with the consent of a parent or guardian.
Because we do not collect names, contact details, or other personal information, we do not hold any personal information about children.
If a parent or guardian contacts us asking for data to be deleted, we will do what we can. Information held on the device, such as story progress, is erased by deleting the App from the device. As for the statistics, we do not hold them in a form that identifies individuals, so we cannot select and delete the information of one particular person. We ask for your understanding on this point.
8. Contact
For questions or requests about the App or this privacy policy, please contact us at:
As this is run by one person, it may take some time to reply. We appreciate your understanding.
9. Changes to this policy
We may revise this privacy policy as features are added to the App or as laws change.
If we revise it, we will update this page and change the revision date below. If we make a significant revision that changes the kinds of information handled, we will also try to let you know within the App.
10. Dates
Established: 1 October 2026
Revised: 17 October 2026
IMUSTERA