Saikou Privacy Policy

Effective date: 1 November 2026

In plain English

Saikou has no account, no server, no ads and no analytics. The developer receives no data from the app. If you turn on Google Drive sync, your library data goes to your own Google Drive and nowhere else. If you sign in to MyAnimeList or AniList, the reading progress of the titles you choose to link goes to your own list on that site and nowhere else.

1. Who is responsible

Saikou is made by an individual developer. For any privacy question, write to shinsaikou@proton.me.

2. What stays on your device

Your library, categories, reading progress, reading history, bookmarks, downloaded chapters and settings are stored in the app's private storage on your device. Backups you create are files you choose where to save. None of this is sent to the developer.

If you use MyAnimeList or AniList tracking, the link between a library entry and its entry on that site, with the status, chapter count, score and dates the site last answered, is stored on your device too. So is each sign-in: a token, and the account name shown in Settings, plus, for AniList, the account's AniList id and the scoring system your list uses. A backup file includes those sign-ins only when you tick "Private settings" when creating it; otherwise the file holds no tracker login.

3. What the app sends over the network

Content you browse and read. Saikou fetches pages and images directly from the third-party websites you choose to add. Those websites receive your requests and your IP address, as they would from a web browser, and handle them under their own policies.
Google Drive sync, if you turn it on. Described in section 4.
WebDAV sync, if you turn it on. Your library data is sent to the WebDAV server address you enter, with the credentials you enter. The developer does not operate that server.
MyAnimeList tracking, if you sign in. Described in section 5. Nothing is sent until you sign in, and then only about the titles you choose to link.
AniList tracking, if you sign in. Described in section 6. Nothing is sent until you sign in, and then only about the titles you choose to link.
Nothing to the developer. There is no server run for Saikou.

4. Google Drive sync and your Google data

Permission requested. Only https://www.googleapis.com/auth/drive.appdata. It lets Saikou create, read, change and delete files in its own hidden app data folder in your Google Drive. It gives no access to any other file in your Drive, and those files are not visible in the Drive app.
What is stored there. Your library with each entry's notes, display settings and any title or description you edited, your categories, chapter progress, reading history, bookmarks and tracking entries. Settings, passwords, logins, installed extensions, custom covers and downloaded chapters are not synced.
Your account's email address. After you sign in, Saikou asks Drive for the email address of the signed-in account, so the Sync settings screen can show which account each device uses. It is kept on the device and not sent anywhere else.
Sign-in tokens. Google issues Saikou a token that lets it reach your app data folder without asking you to sign in each time. The token is stored on your device, encrypted with a key held in the Android Keystore, and is never sent to anyone but Google.
Limited Use. Saikou's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements. Data from Google is used only to sync your library between your own devices. It is not transferred to anyone, not used for advertising, and not read by any person.
Stopping sync. Sign out in Saikou's Sync settings, or remove Saikou from your Google Account's third-party connections page. To delete the synced copy, open Google Drive on the web, go to Settings, then Manage apps, find Saikou and choose "Delete hidden app data".

5. MyAnimeList tracking

Off until you sign in. MyAnimeList tracking does nothing, and sends nothing, until you sign in to MyAnimeList in Saikou's Tracking settings.
Signing in. Saikou opens MyAnimeList's sign-in page in your browser. You enter your MyAnimeList password there, on MyAnimeList's own site, never in Saikou. The browser hands a one-time code back to Saikou on the device itself. Saikou exchanges it with MyAnimeList for a sign-in token and asks MyAnimeList for the account's name, so the Tracking settings can show who is signed in.
What is sent to MyAnimeList. When you link a title: the search text (the entry's title, or what you type) and then, for the entry you pick, its status, the number of chapters read, the score, the start and finish dates and whether you are rereading. After that, each chapter you finish in the reader, and each chapter you mark as read, is sent as a new chapter count, in the background once the device has a connection, with retries if it fails. Edits you make in an entry's tracking sheet (status, chapters, score, dates) are sent at once. Both automatic updates can be turned off in Settings, under Tracking. Nothing is sent about titles you have not linked.
What is read from MyAnimeList. Search results, with their cover images loaded from MyAnimeList, and the current state of a linked entry when you open its tracking sheet or an automatic update runs. If a linked entry is no longer on your MyAnimeList list, that reading adds it back with the status and progress Saikou holds.
Your IP address. Every request goes from your device straight to MyAnimeList, which receives your IP address as it would from a web browser and handles it under its own policies.
The sign-in token. MyAnimeList issues Saikou a token that lets it reach your list without asking you to sign in each time. It is stored in the app's private storage on your device, alongside its settings, and is sent to no one but MyAnimeList. Unlike the Google sign-in token in section 4, it is not additionally encrypted with an Android Keystore key. When it expires, Saikou renews it with MyAnimeList; if MyAnimeList refuses the renewal, Saikou stops sending until you sign in again.
Sync and backups. Google Drive sync and WebDAV sync carry your tracking entries between your devices, as section 4 says, but never the MyAnimeList sign-in, which stays on each device. A backup file includes the sign-in only when you tick "Private settings" when creating it.
Nothing to the developer. Tracking calls go from your device to MyAnimeList and nowhere else. The developer sees none of them.
Stopping tracking. Sign out in Saikou's Tracking settings. That deletes the token from your device and Saikou stops sending; a copy of the account name may stay in the app's settings until you sign in again or clear the app's storage. Your entries on MyAnimeList stay as they are. Removing a title's tracking in Saikou deletes the link on the device only, unless you tick "Also remove from MyAnimeList", which also deletes that entry from your MyAnimeList list.

6. AniList tracking

Off until you sign in. AniList tracking does nothing, and sends nothing, until you sign in to AniList in Saikou's Tracking settings. Signing in to MyAnimeList does not sign you in to AniList, or the other way round.
Signing in. Saikou opens AniList's sign-in page in your browser. You enter your AniList password there, on AniList's own site, never in Saikou. When you approve Saikou, the browser hands a sign-in token back to Saikou on the device itself. Saikou then asks AniList for the account's id, name and the scoring system your list uses, so the Tracking settings can show who is signed in and scores appear the way your list shows them.
What is sent to AniList. When you link a title: the search text (the entry's title, or what you type) and then, for the entry you pick, its status, the number of chapters read and whether the entry is private on your list; if the entry is already on your list, its score and its start and finish dates are sent back with it. After that, each chapter you finish in the reader, and each chapter you mark as read, is sent as a new chapter count, together with the entry's status, score, dates and privacy, in the background once the device has a connection, with retries if it fails. Edits you make in an entry's tracking sheet (status, chapters, score, dates, and "Track privately" or "Track publicly") are sent at once. Both automatic updates can be turned off in Settings, under Tracking. Nothing is sent about titles you have not linked.
What is read from AniList. Search results, with their cover images loaded from AniList, and the current state of a linked entry on your list when you link it, open its tracking sheet or an automatic update runs. If a linked entry is no longer on your AniList list, that reading adds it back with the status and progress Saikou holds.
Your IP address. Every request goes from your device straight to AniList, which receives your IP address as it would from a web browser and handles it under its own policies.
The sign-in token. AniList issues Saikou a token that lets it reach your list without asking you to sign in each time. It is stored in the app's private storage on your device, alongside its settings, and is sent to no one but AniList. Like the MyAnimeList token, it is not additionally encrypted with an Android Keystore key. AniList's token cannot be renewed: a year after you sign in, or as soon as AniList refuses it, Saikou stops sending and asks you to sign in again. Updates still waiting are kept and sent after you do.
Sync and backups. Google Drive sync and WebDAV sync carry your tracking entries between your devices, as section 4 says, but never the AniList sign-in, which stays on each device. A backup file includes the sign-in only when you tick "Private settings" when creating it.
Nothing to the developer. Tracking calls go from your device to AniList and nowhere else. The developer sees none of them.
Stopping tracking. Sign out in Saikou's Tracking settings. That deletes the token and the account's id from your device and Saikou stops sending; a copy of the account name and its scoring system may stay in the app's settings until you sign in again or clear the app's storage. Your entries on AniList stay as they are. Removing a title's tracking in Saikou deletes the link on the device only, unless you tick "Also remove from AniList", which also deletes that entry from your AniList list.

7. What the developer collects

Nothing. Saikou contains no analytics, no crash reporting, no advertising and no advertising identifiers, and it has no user accounts.

8. Keeping and deleting data

Data on your device stays until you delete it in the app, clear the app's storage, or uninstall Saikou. Data in your Google Drive app data folder stays until you delete it as described in section 4. Data on a WebDAV server stays until you delete it from that server. Your MyAnimeList and AniList sign-ins stay on your device until you sign out in Saikou, clear the app's storage or uninstall Saikou. Entries on your MyAnimeList or AniList list stay until you delete them there, or from Saikou as described in sections 5 and 6.

9. Children

Saikou is not directed at children and does not knowingly collect data from them.

10. Your rights

The developer holds no personal data about you, so there is nothing for the developer to give you a copy of or delete. Your data is on your devices and in storage you control. If you believe your data is being handled unlawfully, you can complain to the data protection authority in your country.

11. Changes

If this policy changes, the new version is published on this page with a new effective date.

12. Contact

shinsaikou@proton.me