Privacy policy.
Effective and last updated: October 9, 2026
Your learning history belongs to your account. Here’s what Tsumiki stores, why it’s needed, and how to request its deletion.
01Who we are and what this policy covers
Lotus Roots operates Tsumiki, a Japanese vocabulary and kanji learning app. This policy explains how we handle personal information in Tsumiki, on the Lotus Roots website, and when you contact us. It covers account sign-in, dictionary use, vocabulary and kanji decks, introductory learning sessions, typed-answer practice, spaced-repetition reviews, offline use, and progress synchronization.
For privacy questions or requests, contact lotusrootssupport@gmail.com. This policy describes the current service; planned features are not treated as already collecting information.
02Information we handle
Account and sign-in information
When you sign in with Google, or Apple where available, our authentication service receives a provider identifier and account details made available by that provider, which may include your email address, name, and profile picture. Apple may supply a private relay email address. We use an internal account ID to associate your learning data with you. Authentication sessions and tokens keep you signed in. We do not receive your Google or Apple password.
Learning activity and preferences
We store the vocabulary and kanji you select, deck memberships, your learning collection, introduction status, study settings and daily limits. For each question type, we store learning state, review dates, due dates, ratings or answer outcomes, repetitions, lapses, scheduling parameters, and related review history. Review records may include response time, study date, time-zone offset, and the card state before and after a review. A randomly generated installation identifier helps reconcile activity from different devices; it is not an advertising identifier.
Typed answers and dictionary use
Typed practice answers are evaluated on your device. The current review-sync implementation sends review outcomes and scheduling records, rather than the text of each typed answer. Dictionary searching uses the on-device dictionary. The app keeps up to 20 recently opened dictionary entries locally; ordinary search queries and this recent-entry list are not included in learning sync. Entries you choose to study, and associated dictionary content, become part of your synced collection.
Support and technical information
If you contact us, we receive your email address, message, and any attachments or diagnostics you choose to provide. Our hosting, authentication, and delivery providers may process IP addresses, request timestamps, browser or device information, and operational or security logs when providing their services. Avoid including passwords, sign-in tokens, or unrelated sensitive information in support messages.
03How we use information
- Create and authenticate your account and maintain your session.
- Provide dictionary, deck, vocabulary, and kanji learning features.
- Schedule reviews and maintain separate progress for different question types.
- Save learning activity offline and synchronize your progress when a connection is available.
- Apply your preferences and maintain shared progress across decks.
- Respond to support and privacy requests, investigate problems, protect the service, and meet applicable legal obligations.
Review scheduling uses your learning activity to decide when to show a question again. It does not make decisions about employment, credit, or other matters with comparable legal effects.
04On-device storage and cloud synchronization
Tsumiki stores its dictionary, learning records, recent dictionary entries, settings, and pending synchronization data on your device. On supported mobile platforms, sign-in tokens use the operating system’s secure storage. Other app data is kept in local databases or application storage; we do not claim that every local record is separately encrypted.
Account and learning information is also stored through Supabase to support authentication and synchronization. Changes made offline may remain on your device until sync succeeds. Signing out or uninstalling the app does not by itself delete your cloud account. Signing out also should not be treated as a complete erasure of local databases or caches. Device backups may retain app data under your operating-system or backup-provider settings.
06Website storage and links
The current Lotus Roots pages do not add advertising cookies, analytics scripts, or embedded social trackers. Hosting infrastructure may use necessary technical storage and process request logs. External sign-in, store, support, and other linked services have their own privacy practices. This policy does not govern those services’ independent activities.
07Retention
We retain account and learning records while they are needed to provide your account, preserve long-term learning progress, and synchronize devices, unless you request deletion. Local data remains until removed through the app’s storage controls available on your device, or removed with the app, subject to device backups.
Support correspondence and operational records are retained only as reasonably needed to resolve requests, maintain security, comply with legal obligations, and address disputes. We do not currently promise a single fixed retention period for all provider logs and backups. Deleted data may remain temporarily in restricted backups until those backups expire through the provider’s retention cycle. Any information retained for a legal or security reason is limited to that purpose.
08Request account or data deletion
You can request deletion without having the app installed. Email lotusrootssupport@gmail.com with the subject “Tsumiki account deletion”, preferably from the email associated with your Tsumiki account. If you used Apple’s private relay or no longer have access to that email, explain this so we can help verify ownership. Do not send a password.
We may request limited additional information to verify that the account belongs to you. After verification, we will delete your Tsumiki authentication account and associated cloud profile, preferences, deck subscriptions, collection selections, question schedules, and review history, except information we must retain for legal or security reasons. We will explain any applicable exception and respond without undue delay, within deadlines required by applicable law.
Account deletion does not delete your Google or Apple account, other users’ data, or the public dictionary and shared deck content. It also cannot remotely erase copies held on offline devices or in device backups. After confirming that any data you want to keep is saved, clear Tsumiki’s app storage or remove the app on your devices to remove local copies; manage backups separately. We will provide relevant instructions when handling your request.
You may also contact us to request access, correction, an export, or deletion of particular information. Tell us which information your request concerns.
09Your choices and privacy rights
You can adjust available study preferences, stop using the service, manage connected-app permissions with your sign-in provider, and contact us about your information. Revoking sign-in permission is not the same as asking Lotus Roots to delete your account.
Depending on where you live, you may have rights to access, correct, delete, or obtain a copy of personal information; restrict or object to certain processing; withdraw consent where processing relies on it; and complain to your local data protection authority. We will assess requests under the laws that apply to you and may verify your identity before acting.
Where a legal basis is required, we process information to provide the service you request, for legitimate interests such as security and support, to comply with legal obligations, or with consent where required. Withdrawing consent does not affect processing that was lawful before withdrawal.
10Security and international processing
We use HTTPS for app-to-service communications, account authentication, and access controls designed to separate users’ cloud records. No storage system or transmission method can be guaranteed completely secure. Protect your device and sign-in account, and contact us if you suspect unauthorized access.
Our service providers may process information in countries other than your own, where privacy laws may differ. Where required, we use the applicable provider arrangements and legally required safeguards for international transfers. Contact us for information about arrangements relevant to your account.
11Age requirements
Tsumiki is intended for people aged 13 and older and is not directed to children under 13. We do not knowingly collect personal information from children under 13. If you believe a child under 13 has provided information, contact us so we can investigate and take appropriate deletion steps. Where local law requires a higher age or parental authorization, those requirements also apply.
12Changes and contact
We may update this policy as the service or applicable requirements change. The date above identifies the latest revision. We will provide additional notice of material changes when required. Any new feature involving materially different information use will be covered by an updated policy and any required permissions.
Lotus Roots — Tsumiki
Website: lotusroots.org
Privacy and support: lotusrootssupport@gmail.com