The AI-powered toolkit for turning Japanese lyrics into language mastery.
Live site: kashikit.com
KashiKit turns any Japanese song into a structured, multi-day language course. Paste a YouTube URL and an LRC lyrics file — the app does the rest.
- Auto-generated courses — splits a song into daily lessons based on how many lines you want to study per day
- AI difficulty ratings — each song is rated 1–5 stars by the AI with a short explanation of why
- Vocabulary cards — click any word in a lyric to see its meaning, furigana, part of speech, grammar notes, and an AI-generated example sentence
- Furigana overlay — readings displayed above kanji using
<ruby>tags - Synchronized video — embedded YouTube player loops the current lyric line automatically
- Sentence bank — real example clips from other songs in your library where the same word appears
- Text-to-speech — pronounce any word with one click using the browser's built-in Japanese voice
- Vocabulary quiz — pre-generated fill-in-the-blank quiz at the end of each lesson
- Dictionary — searchable cache of every word you've studied across all songs
- Progress tracking — lesson progress saved locally in the browser (no account needed)
- Auto lyrics fetch — automatically pulls LRC lyrics from lrclib.net when available
- API usage tracker — monitor your daily Gemini API call count against the free tier limit (1,500/day)
- Framework: Next.js (App Router)
- Database: Turso (cloud libsql/SQLite) in production; local SQLite file in development
- AI: Google Gemini 2.0 Flash for vocabulary extraction, translation, and difficulty assessment
- Styling: Tailwind CSS
- Node.js 18+
- A Google AI Studio API key (free)
git clone https://github.com/yijiang1/KashiKit.git
cd KashiKit
npm install
cp .env.local.example .env.local
# Add your GOOGLE_AI_API_KEY to .env.local
npm run devOpen http://localhost:3000.
By default the app uses a local SQLite file (lyriclearn.db) in the project root. To use Turso in production, set TURSO_DATABASE_URL and TURSO_AUTH_TOKEN in your environment.
- Find a Japanese song on YouTube
- Get the LRC lyrics file (e.g. from lrclib.net — KashiKit can fetch these automatically)
- Click + Import song, paste the YouTube URL and the artist/title, set how many lines per day, and hit Import
- The app processes each line with AI (~1 API call per line) and generates your course
Set ADMIN_MODE=true in your environment to unlock admin-only features:
- Lyrics Editor (
/admin/lyrics-editor) — visually adjust the start/end timestamp of each lyric line against the YouTube player - Sentence bank management — rebuild the cross-song example sentence index
- Song management — import songs, regenerate quizzes, and set difficulty ratings
Admin auth is env-var based — no login screen.
- Progress is stored in
localStorage— no account or server-side session required for visitors - All user data is local; the only external call is sending lyrics to the Gemini API for analysis
- The free Gemini tier allows 1,500 requests/day, which is enough to import several songs per day
MIT