Privacy

Study data and language

Card ratings and review schedules, guide and hands-on progress, practice-answer statistics, and mock-exam state and history are saved in this browser’s localStorage. Search terms and filters are not saved. Your selected language is represented by the URL path (Japanese at / and English at /en/) and is not stored as a separate browser preference. Study data is neither synchronized to a server nor linked to an account.

No third-party analytics or tracking

This site does not load third-party analytics, advertising tags, or behavioral tracking. It also has no feature that sends your study content or progress elsewhere.

For AI agents running in your browser, this app exposes read-only tools (plus one that changes the visible screen) through the draft WebMCP API (document.modelContext). The tools run inside this tab only and make no network requests. Your progress reaches an agent only when an agent running in your browser (including a browser extension) calls a tool, and what happens to it afterwards is governed by that agent, not by this site.

Contact

For questions or correction requests, please open an issue in GitHub Issues (opens in a new tab) ↗.