Last updated 2026-09-07
Kizuna is a personal notebook about the people in your life: who they are, what they like, key dates, reminders and notes. The information you enter is about real people, so this page says exactly where it goes.
Everything you enter is saved in your browser (IndexedDB) on the device you are using. It stays there unless you use one of the two features below. Clearing site data in your browser deletes it. You can export a JSON backup at any time from the home page.
If you sign in with Google and press Back up to cloud, a copy of your data is stored in our Google Cloud project (Singapore region, asia-southeast1), keyed to your Google account. Nothing syncs automatically — each backup and restore is a button press. Only your signed-in session can read or write your copy. Sign-in keeps your Google account id, email, name and picture in a session cookie for up to 7 days; we do not store your Google password and cannot access your Google account.
When you ask for a conversation deck or a next-step suggestion, the selected person’s profile — name, relationship, notes, likes and dislikes, avoid-topics, upcoming reminders and the most recent records — is sent to Google Vertex AI (Gemini) in the same region to generate the suggestion. It is sent only when you press the button, only for that person, and requires you to be signed in. Under Google Cloud’s Vertex AI terms, prompts are not used to train Google’s models. We do not keep a copy of the prompt; the generated cards are stored on your device like everything else.
Delete a person from their edit page — this removes them and everything attached to them on the device. To remove a cloud backup, sign in and back up again after deleting locally, or ask us to delete your cloud copy entirely. Signing out ends your session on that device.
Kizuna is run by its owner as a personal project at kizuna.you. Questions or deletion requests: use the contact details on the account you signed in with, or the project repository if you were given access.