Scope and changes
These terms apply to the Kotomoa website and apps, accounts, learning, review and games, the community, JLPT Mock Tests, and paid products, and are published in the service. If separate consent is requested when you create an account or make a purchase, the applicable terms take effect when you consent. Matters that legally require explicit consent are not treated as accepted merely because you use the service.
When a change in law or the service requires these terms to change, Kotomoa will explain the effective date, reason, and before-and-after details. We will announce ordinary changes in the service at least seven days in advance and material or unfavorable changes at least 30 days in advance. If the law requires separate notice or consent, we will follow that process. A user who does not agree may end the service agreement before the change takes effect.
Service features
- Learning information about Japanese kanji, vocabulary, grammar, radicals, and stroke order
- Review folders, random and fishing games, and learning progress
- Community posts, comments, reactions, polls, and notifications
- JLPT Mock Tests, scoring and results, and purchased access
Kotomoa’s JLPT levels, question composition, and pass guidance are its own study-reference classifications. They are not official lists or exams from the Japan Educational Exchanges and Services or another official JLPT organization, and do not guarantee a passing result.
Accounts and user responsibilities
You must use an accurate nickname that does not infringe another person’s rights and keep your sign-in method and device secure. If you learn of unauthorized use of your account or authentication method, immediately notify moonlab.app@gmail.com.
Using another person’s account; bypassing the service or its security; making automated bulk requests; collecting data without authorization; distributing malware; disrupting operations; or violating law or third-party rights is prohibited. Depending on the severity and urgency, Kotomoa may restrict content, suspend an account, or end access, and will explain the reason and appeal method when possible.
A minor may need consent from a legal representative to purchase a paid product. A contract made without required consent may be canceled under applicable law.
AI teacher terms
AI terms revised: 2026-09-11.2. These clauses apply once you accept them on the AI teacher start screen.
AI Teachers provide Japanese conversation, corrections and learning through Gemma on your device or Google Gemini after sign-in. Learning materials, quizzes and learning records are available alongside conversations. Virtual teachers do not replace a real teacher or certified assessment.
You must comply with Section 3.2 of the Gemma Terms of Use and the Gemma Prohibited Use Policy. Those use restrictions are incorporated into these AI teacher terms. You must not use this feature in violation of applicable law, others' rights, or for purposes prohibited by that policy. The complete policy provided below applies.
AI replies may contain factual, meaning, reading, or grammar errors. Check important information against Kotomoa study materials or other references. No specific learning outcome or exam result is guaranteed. Responsibility for generated replies and their use is governed by applicable law and the service terms.
Guest conversations, memories and journals are stored only in this browser or app. When signed in, conversations, corrections, quiz attempts, user memories, learning journals and synchronization consent records are stored per account on Kotomoa servers for access across devices and deleted when the account is deleted. Guest and account records are separate; guest records are never uploaded or merged into an account. Account learning records are not retained in persistent device storage. Model and voice preferences and device consent receipts are kept separately per account on this device. Local inference does not send conversations to an external AI server, but signed-in learning records are saved to Kotomoa servers. With Gemini selected, relevant recent conversation, your input, related memories and learning materials are sent through the Kotomoa backend to Google Cloud. Speech sends only the selected response text. Do not enter sensitive information or other people’s personal data. Take care on shared devices and when deleting site data.
When furigana, translation or analysis is enabled, the response text is processed by Kotomoa’s server-side morphological analyzer. Local-model reply and translation generation, and analysis of unregistered expressions, run on your device without transfers to external AI or translation providers. Signed-in conversation history is saved to your account as described in the storage notice. For Gemini-model responses, the response text is sent through the Kotomoa backend to the Google Cloud Translation API for automatic translation by Google Translate; analysis of unregistered expressions uses the corresponding Gemini model. These auxiliary requests and results are not saved to the usage database, conversations, memories or journal and are used only in the current view.
THIS SERVICE MAY CONTAIN TRANSLATIONS POWERED BY GOOGLE. GOOGLE DISCLAIMS ALL WARRANTIES RELATED TO THE TRANSLATIONS, EXPRESS OR IMPLIED, INCLUDING ANY WARRANTIES OF ACCURACY, RELIABILITY, AND ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
Scenes are Japanese roleplays in which Gemini generates and advances goals, counterpart dialogue and actions as text for the selected role and situation. Background image generation uses only fal.ai. Similar images in the shared background library are reused first; only when none is available is a visual prompt sent to fal.ai. Scene settings, goals, dialogue and progress are stored in your account, available across devices, and deleted when you delete your account. Generated backgrounds are kept in a shared server image library and reused across users in similar scenes. The shared index contains only the location, lighting and visual features, without account details or dialogue transcripts. Shared backgrounds remain after an account is deleted. Counterpart dialogue can be played as speech; generated audio is kept temporarily in screen memory only. AI progress and completion judgments may be wrong and do not make real reservations, purchases or ticket transactions.
Gemini chat, speech and Scenes, Google Translate translations, and fal.ai backgrounds
Reply playback provides signed-in users with AI-generated speech through Gemini 3.1 Flash TTS. Each teacher has a fixed voice; emotional delivery may vary. You can stop playback, replay from the beginning, and turn autoplay on or off in settings. Calls require microphone permission. Speech recognition uses either the device/browser service or Gemini, as selected before the call. Gemini recognition sends your speech to Google Cloud. Built-in recognition uses the browser or operating system provider and may process audio on that provider’s servers; it does not use Kotomoa’s Gemini transcription API. Your microphone and the teacher voice are recorded on the device. Recordings stay in account-specific storage on that device and are not uploaded to Kotomoa or synced to other devices. Call transcripts and duration are saved to your account conversation and journal. You can play and download recordings; clearing site data deletes them.
Google Cloud processes Gemini conversation, correction, speech synthesis, speech recognition, scene goal and progress text, and response translations through the Cloud Translation API as a service provider. For Gemini response translations, the required response text is sent through the Kotomoa backend to Google Translate (Cloud Translation API) for automatic translation. Local-model reply and translation generation run on your device without transfers to external AI or translation providers. However, Kotomoa’s server handles morphological and reference analysis for furigana, translation and analysis displays; signed-in conversation history is saved to your account as described in the storage notice. Required text and microphone utterances from calls using Gemini speech recognition are sent over encrypted connections when requested and may be processed internationally through global endpoints. Google's processing and retention conditions follow its service-specific terms, applicable data processing terms and data governance notices; the relevant Preview conditions apply to Gemini Preview models. Background image generation uses only fal.ai, an external AI service. A visual prompt for the scene background is sent when no reusable shared background is available. Transfers to fal.ai are also encrypted and may be processed internationally. Its processing, retention and use restrictions follow its Terms of Service, Privacy Policy, Acceptable Use Policy and data retention documentation. Use local teacher chat with speech and Gemini assistance turned off, and do not use Scenes, to avoid these external AI transfers. Inputs or outputs that violate either provider's acceptable use policy, unauthorized impersonation and deceptive use of synthetic voices are prohibited.
Each Gemini conversation, correction, speech synthesis, speech recognition, scene planning and scene turn request records the account, request identifier, teacher, model, voice, processing time, status and provider-reported token counts on the server. Successful fal.ai background generation requests are counted separately. Per-request prices and estimated costs are not stored; costs are calculated at query time using administrator-defined, effective-date formulas, aggregated Gemini tokens, and successful fal.ai request counts with a fixed per-request rate. Conversation text, audio and images are not stored in the usage database. Local usage separately records a hashed device identifier and device-reported tokens and time. Offline records may be sent after reconnection. These records support usage review, cost estimation and troubleshooting, and do not automatically charge users. Any paid service will disclose prices and payment conditions and obtain separate consent.
Local Gemma use requires legal capacity and necessary consent. Under Google Cloud generative AI terms, Gemini conversation, speech and scenes are restricted to users aged 18 or older. Preview model terms and availability can change, and unless otherwise specified their data processing conditions may differ from generally available services; do not submit personal or regulated information. Violations may result in restricted access.
Legal copies and distribution notice
The English originals and notice below are included with the web and app distributions. Explanations do not grant additional rights or relax the original use restrictions.
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Community and user content
Rights in posts, comments, attachments, and other user content generally remain with the author. You grant Kotomoa a non-exclusive license necessary to operate the service and to store, reproduce, display, and transmit the content and provide search, reporting, and backup features. This license is limited to providing the service.
You may post only content you have the right to post. You must not post unlawful or harmful content, privacy violations, impersonation, hate or harassment, spam, or copyright-infringing content. Kotomoa may hide or delete content under applicable law, a rights holder’s request, or the operating policy.
Posts and reply context may remain after account deletion. We remove the original nickname and display the author as “Deleted user.” You may delete content before deleting your account or request deletion by email afterward. Processing may be limited when another user’s rights, a dispute, or a legal retention basis applies.
Community auto-translation uses Google Translate (Cloud Translation API). When auto-translation is enabled and a post’s original language differs from the interface language, the required title and body text is sent through the Kotomoa backend to Google for translation and may be processed internationally. Translations are cached in the database and reused; the original is preserved. The original may be displayed when a translation is unavailable or fails. Automatic translations may contain errors, so refer to the original when accuracy matters.
Google Translate · Cloud Translation API · Read the Google translation disclaimer
Paid products and access rights
Current paid products provide one-time access to an individual JLPT Mock Test or a bundle and are not subscriptions. Sessions 1 and 2 for each level may be free, while sessions 3 and 4 may require purchased access. The price and availability shown on the purchase screen and by the payment provider take priority.
The purchase screen shows the product, price, supply start time, access period, and withdrawal restrictions. Terms shown for an individual transaction apply together with these terms but cannot limit consumer rights under applicable law.
Purchased access becomes active after a transaction confirmed by the payment provider is correctly linked to the Kotomoa account. A payment-complete screen or client event alone does not establish access. Access may be suspended or revoked if a refund, cancellation, chargeback, or fraudulent transaction is confirmed.
Operator and seller information
- Service operator: Kotomoa
- Business / representative: Moon Lab / JIHYEON MOON
- Business registration number: 485-12-02992
- Contact: moonlab.app@gmail.com
Moon Lab supplies Kotomoa’s paid products and provides access rights. For Paddle web purchases made by customers in South Korea, Paddle.com Market Limited acts as an authorized reseller and Merchant of Record, handling payment, receipts, tax, and refunds, while the product-use agreement is between Moon Lab and the user. For Paddle entities in other regions and purchases through the App Store or Google Play, the merchant of record and payment processor are identified on the purchase screen and receipt.
Withdrawal and refunds
You may request withdrawal within seven days after receiving the written contract information. If content supply begins later, the period starts when supply begins. Withdrawal for a portion of digital content whose supply has begun may be restricted only when the legally required advance notice and measures such as trial or temporary access have been provided. The restriction does not apply to an unsupplied portion of a divisible contract.
If you select “Start Exam” for a paid JLPT Mock Test and the questions begin to be provided, supply of that content is considered to have started. If the requirements of applicable law are met, withdrawal based solely on a change of mind may be restricted.
If a product differs from its description or advertising, or is not performed as agreed, you may request withdrawal, termination, or correction within three months after supply or within 30 days after you knew or reasonably could have known of the issue.
Refunds should first use the process and original payment method of the merchant of record shown on the purchase receipt (Paddle, the App Store, or Google Play). If Moon Lab is responsible for the refund, it will process it within the time and by the method required by law. A payment provider’s policy and these terms do not limit statutory rights.
For help verifying access, send the receipt transaction ID, purchase channel, product, purchase date and time, and your Kotomoa nickname to moonlab.app@gmail.com. Do not send a password, full card number, or original authentication or purchase token.
Intellectual property and data sources
Rights in Kotomoa’s software, screens, compilations, and original content belong to Kotomoa or the lawful rights holder. Public data and third-party materials such as fonts and media remain subject to their original copyrights and licenses. See Data Sources for details.
You may use the service for personal learning. Without separate permission, you may not reproduce, redistribute, or sell all or a substantial part of the service or use it to build a database. When an applicable open license separately grants rights, that license takes priority.
Advertising and external services
The web service may display advertising, and Google, Apple, Paddle, YouTube, or X services may be used for sign-in, payment, or embedded content. The provider’s terms also apply to outages, policies, and transactions involving an external service. If an ad-removal product is offered, the applicable platform, period, and scope will be shown separately on the purchase screen.
Service changes and interruptions
Kotomoa may change or interrupt all or part of the service for reasonable grounds such as maintenance, security, changes in law or provider policy, natural disasters, or communications failures. We will give advance notice of significant foreseeable interruptions when reasonably possible. If essential use of paid access remains unavailable for an extended period, we will provide correction or refund procedures under applicable law.
Warranties and limits of liability
Kotomoa works to provide accurate learning materials and a reliable service, but does not guarantee learning outcomes, exam results, fitness for a particular purpose, or uninterrupted use. You should also consult official materials before making an important learning, exam, or transaction decision.
For free services and losses caused by the user, third-party services, or force majeure, Kotomoa’s liability may be limited to the extent permitted by law when Kotomoa has not acted intentionally or with gross negligence. Nothing limits Kotomoa’s liability for intentional misconduct or gross negligence, statutory consumer rights, or liability that cannot legally be excluded.
Ending service and deleting an account
You may delete your account at any time in account settings. After deletion, you can no longer use sign-in, review progress, or active purchased access. The minimum records needed for transaction restoration, refunds, abuse prevention, and exam-result integrity may remain under the Privacy Policy.
Governing law and disputes
The laws of the Republic of Korea govern these terms and use of the service. If a dispute arises, first contact moonlab.app@gmail.com to try to resolve it. If it is not resolved, it will be handled by a court with jurisdiction under applicable laws, including South Korea’s Civil Procedure Act.
Effective date
These terms take effect on August 24, 2026.