Shiritai is a Chrome extension that turns any web page into a Japanese reading lesson. Toggle furigana on and readings appear above every kanji—on X, Threads, blogs, news, anywhere. The reading engine runs locally, so it's fast and private. Select any text → Explain for a study card: translation, grammar, vocab, kanji, JLPT level, and the casual nuance dictionaries miss. Built for N5–N2 learners reading real Japanese. A companion web app explains any pasted text the same way.