Disclaimer

Hitoiki Arcade and Hitoiki Learning are for entertainment and refreshing your knowledge. This page explains how to understand the information and records provided by the site.

Information and learning results

We take care with accuracy, but information may contain errors or change when its sources are updated. Before using information for an important decision, also check the latest material from the source provider or relevant public authority. You can report an error through the feedback form.

Quiz scores and game results help you review your activities on this site. They do not replace qualification examinations, certification of ability or assessment by a professional.

News and reference dates

News questions display a reference date, expiry date and sources. Their explanations are based on information as of that reference date and do not reflect every later announcement or change. Check primary sources from the relevant organizations for the latest situation.

Local saves and backups

Supported game and quiz progress and records are kept on the device and in the browser you use. We do not provide account synchronization or backups of these records on the operator’s server. Records can be lost when browser data is cleared, settings change or a device fails. Where supported, export a backup file to keep records you need. Each activity page and Saves & controls explain the available save and backup functions.

Assets & licences

Images and designs use SVG/CSS created for this project, and move sounds are generated with short Web Audio waveforms. Body text and controls use M PLUS Rounded 1c; titles use Kiwi Maru. Font files are served by this site. Both fonts are licensed under the SIL Open Font License 1.1.

We also use third-party libraries and engines, including React, React DOM, chess.js, GNU Go and Fairy-Stockfish. Check each licence before using or redistributing materials or programs. Copyright notices, licence texts and corresponding engine sources are available in Assets & licences. This disclaimer does not override those licence conditions.

About analytics

We use Google Analytics (GA4), provided by Google LLC, to improve the site. Measurement and prior permission follow regional conditions and your preferences. We respect opt-outs and browser Global Privacy Control (GPC) signals. Google receives page URLs without queries or fragments, device and browser information, cookie identifiers and supported interaction events. The analytics implementation does not send game boards or input, selected quiz answers, correctness, scores or learning-history contents, backup contents or feedback text.

Analytics cookies expire after 90 days. GA4 retention for user-level and event-level data is set to 14 months; new activity resets the user-identifier retention period. This setting does not apply to standard aggregated reports. Data may be processed outside your country at facilities maintained by Google or its subprocessors.

See About analytics for the full explanation of sent information, purposes, regional conditions and recipients. At the end of that page you can choose Stop analytics or change your preferences. Games, quizzes and local saves remain available when measurement is stopped. Reading this page is not consent, and stopping future measurement does not immediately delete all information already sent.

Regional classification data

To apply regional analytics conditions, we estimate the country from the connection IP locally on our server. We do not request device location or use GPS, and do not send your IP to an external geolocation API for this classification. The country result is not stored. IP-based estimates can be incorrect and do not determine legal residence.

Country data comes from DB-IP IP to Country Lite, licensed under Creative Commons Attribution 4.0 International (CC BY 4.0). See the official DB-IP information for the provider and licence conditions.

External information and links

Source links lead to information provided by external organizations and websites. Content, locations and terms of use may change. Check the linked provider’s latest information and terms when needed.

Rights and responsibilities under law

This notice does not restrict users’ rights or the operator’s responsibilities under applicable law. It does not establish exemptions or limitations of responsibility that conflict with applicable law. Applicable law takes precedence.