Terms of Service

Established: July 20, 2026 / Last updated: October 11, 2026

These Terms of Service ("these Terms") set out the conditions for using the Android application "Poppin", the version of it that runs in a browser (the "browser version"; together with the Android application, the "App"), and the website poppin-studio.com (the "Site"; together with the App, the "Service"), provided by Poppin Studio ("we", "us"). By using the Service, users are deemed to have agreed to these Terms.

This English version is provided for convenience. If it differs from the Japanese version, the Japanese version prevails.

Article 1 (Application)

  1. These Terms apply to all matters relating to the use of the Service.
  2. Rules we post separately on the Service (including the Privacy Policy) form part of these Terms.
  3. Where these Terms conflict with the rules in the preceding paragraph, those rules prevail.

Article 2 (The Service)

  1. The App is an application that provides studying with flashcards and spaced-repetition scheduling, and a feature that measures the time spent in other apps the user specifies and shows study pops when certain conditions are met ("Pop Quiz").
  2. The browser version is for making, editing and studying decks and cards in a browser on a computer or similar device. It does not provide Pop Quiz, ads, or purchase of the paid feature.
  3. The App's specific features, specifications and requirements are published on its Google Play listing, on the Site, and in other places we designate.

Article 3 (Conditions of Use)

  1. The Service is provided on the assumption that it is used on an Android device or, for the browser version, in a browser we have confirmed it works in.
  2. The Service is not directed at children under 13. Children under 13 may not use the Service.
  3. Users use the Service at their own responsibility and accept all risks that come with it.
  4. The browser version cannot be used without signing in with a Google account. Signing out of the browser version deletes the decks, cards and settings saved in that browser (anything already synced to our server is not lost). Changes not yet synced may be lost if the user signs out before syncing or if the browser deletes its storage.
  5. A user who stays signed in to the browser version (who selects "Keep me signed in") understands that others using that browser can view or change their decks, and is responsible for managing this, for example by not selecting it on a shared computer.

Article 4 (Prohibited Conduct)

When using the Service, users must not:

  1. Break the law or public order and morals
  2. Copy, modify, adapt, redistribute, sell, lend, reverse engineer, decompile or disassemble the App (except as expressly permitted by applicable law)
  3. Interfere with the proper running of the Service, or cause disadvantage or damage to us or third parties
  4. Access our server other than through the App, or more often than normal use of the App requires
  5. Use any feature of the App, including Pop Quiz, beyond the study purpose the user set, to interfere with the normal use of apps on another person's device against that person's will (continuing to use Pop Quiz after setting target apps and conditions for one's own study is not prohibited conduct under this item)
  6. Use the storage of sync for purposes other than studying in the App (such as storing or distributing files), or evade the storage limit, for example by using several accounts
  7. Sign in with another person's Google account, or otherwise use false information
  8. Infringe intellectual property or other rights relating to the Service
  9. Do anything else we reasonably judge to be inappropriate

Article 5 (User Content)

  1. Copyright and other rights in the decks, cards and accompanying media files a user makes or imports in the App ("User Content") belong to the user or the rightful owner.
  2. User Content is saved on the user's device (in the browser version, in the browser's storage) and, when the user signs in with a Google account and uses sync, also on a server we manage. We do not look at User Content, except as needed to run the Service, investigate faults, deal with misuse, and comply with the law.
  3. User Content saved on our server may be deleted without prior notice when the storage period set out in the Privacy Policy ends. If use in breach of the preceding Article comes to light, we may also delete that User Content, or suspend the use of sync, without prior notice. User Content on the device is not lost by these deletions.
  4. Users can delete their User Content saved on our server at any time with "Delete cloud data" in the App. Deleted content cannot be restored.
  5. Users warrant that their User Content does not infringe the rights of third parties, and will resolve any claim of infringement at their own cost and responsibility.
  6. When importing a deck received from another person, users are to check, within reason, that its contents do not infringe the rights of third parties.

Article 6 (Paid Feature)

  1. Some features of the App are provided as a paid feature (Poppin Pro). It is purchased through Google Play from the Android application, as a monthly or yearly auto-renewing subscription, and renews automatically at the end of each period unless cancelled. It cannot be purchased from the browser version.
  2. A user who is a minor uses the Service (including purchasing the paid feature) with the consent of a parent or other legal guardian.
  3. The paid feature consists of not showing ads in the Android application and increasing the storage of sync from 5 GB to 20 GB. The increased storage also applies to the browser version signed in with the same Google account.
  4. When the paid feature ends, ads are shown again and the storage returns to 5 GB. If more than 5 GB is stored at that time, sync cannot save anything new until the amount is 5 GB or less (saved data can still be read and deleted). If 6 months pass in this state, the stored data is deleted in accordance with the Privacy Policy.
  5. The subscription can be cancelled at any time, and remains available until the end of the period already paid for. Cancellation, revocation and refunds are governed by Google Play's terms.

Article 7 (Ads)

Ads are shown in the Android application through Google AdMob. Revenue from these ads goes toward running the Service. In regions where the law requires consent, the App asks for consent to, or offers the opportunity to refuse, the use of information for advertising. See the Privacy Policy for how to change advertising choices and for how the advertising ID and other information are handled. The browser version shows no ads.

Article 8 (Exclusion of Antisocial Forces)

  1. Users represent and warrant that they are not, and have no relationship with, organised crime groups, their members, quasi-members or affiliated companies, corporate racketeers, or similar persons ("Antisocial Forces").
  2. If we judge that a user has breached the representation and warranty in the preceding paragraph, we may suspend that user's use of the Service without prior notice.

Article 9 (Disclaimer)

  1. The Service is provided as is. We make no warranty, express or implied, as to its completeness, accuracy, reliability, usefulness, fitness for a particular purpose, or continued availability.
  2. We are liable for damage to users arising from the use of, or inability to use, the Service only where we are at fault.
  3. Where damage to a user arises from our slight negligence (negligence that is not gross), the amount we pay is limited to ordinary, direct damage, and capped at the greater of the amount the user paid for the paid feature in the 12 months before the event causing the damage, or one month's price of the paid feature at the time of that event. This cap does not apply to our wilful misconduct or gross negligence.
  4. The App saves decks and cards on the device and on the server, but the possibility of data being lost through faults cannot be ruled out entirely. Users can keep copies of important decks using the App's export feature and similar means.

Article 10 (Changes, Suspension and Discontinuation of the Service)

  1. We may suspend the Service temporarily for maintenance, to deal with faults, or for other operational reasons. We may also change the content of the Service, or suspend or discontinue it, without prior notice. Damage to users or third parties arising from this is governed by paragraphs 2 and 3 of the preceding Article.
  2. If we discontinue sync, we will announce it in the App or on the Site at least 30 days before the planned end date, except where legal or security reasons or other unavoidable circumstances prevent this. We will endeavour to provide the means for users to move the User Content saved on our server to their devices (sync and export) until the planned end date.

Article 11 (Changes to These Terms)

We may change these Terms, in accordance with Article 548-4 of the Civil Code of Japan, where:

  1. The change is in the general interest of users; or
  2. The change does not go against the purpose of the contract and is reasonable in light of the need for it, the appropriateness of the changed content, and other circumstances.

When we change these Terms, we will announce the changed Terms and the date they take effect in the App or on the Site before that date. Changes that restrict users' rights or increase their burden will be announced at least 14 days before they take effect.

Article 12 (Governing Law and Jurisdiction)

These Terms are governed by and interpreted under the laws of Japan. The Tokyo District Court has exclusive jurisdiction in the first instance over any dispute relating to these Terms or the Service. However, where a user is a consumer and the law of the user's country of residence mandatorily applies a different rule, that rule applies.

Article 13 (Contact)

For questions about these Terms, contact:

Poppin Studio Email: contact@poppin-studio.com