Waifu – Privacy Policy
Last updated: September 28, 2026
Waifu ("the app") is made by an independent developer (contact: nathanlinshuo@gmail.com). This policy explains what data the app uses and why.
Who the app is for
The app is intended for adults aged 18 and over. We do not knowingly collect data from anyone under 18.
Data stored on your device
Your progress (coins, purchases, affection levels, episodes read, outfits, settings), the name you choose, and your chat history are saved on your device. We do not run our own servers and do not keep copies of this data. Uninstalling the app deletes it.
AI chat
When you send a message to a character, the text of your message, the recent conversation, the name you chose, and short notes the character keeps about what you told her (for example "has a cat named Mochi") are sent to Google's Gemini models through Google Firebase AI Logic to create her reply. This data is processed by Google under the Google Cloud and Firebase terms (https://firebase.google.com/terms) and is not used by us for any other purpose. Please do not share sensitive personal information in chats. Replies are generated by AI and may be inaccurate; you can report any reply inside the app by long-pressing it.
App integrity
To protect the AI service from abuse, the app uses Firebase App Check with Google Play Integrity, which lets Google confirm that requests come from a genuine copy of the app on a genuine device.
Advertising
The app shows rewarded video ads through Google AdMob. AdMob may collect your device's advertising ID, IP address (approximate location), and information about ad interactions to show and measure ads. In regions where consent is required, you are asked for consent first, and you can change your choice anytime in Settings > Privacy choices. See https://policies.google.com/technologies/ads.
Purchases
Purchases and subscriptions are processed by Google Play. We receive only a purchase confirmation, never your payment details.
Notifications
If you allow notifications, the app uses them only to tell you when a focus session has finished.
Analytics
The app does not use analytics or crash-reporting services.
Your choices
Your data is kept only on your device. You can delete your chat history with a character from the chat menu, and delete all app data by uninstalling the app. We do not keep copies of your chats or progress, so there is no data on our side to delete. For questions, contact nathanlinshuo@gmail.com.
Changes
We may update this policy; the date above shows the latest version.